Efficiently replace all accented characters in a string?
A direct port to javascript of Kierons solution: https://github.com/rwarasaurus/nano/blob/master/system/helpers.php#L61-73:
/**
* Normalise a string replacing foreign characters
*
* @param {String} str
* @return {String} str
*/
var normalize = (function () {
var a = ['À', 'Á', 'Â', 'Ã', 'Ä', 'Å', 'Æ', 'Ç', 'È', 'É', 'Ê', 'Ë', 'Ì', 'Í', 'Î', 'Ï', 'Ð', 'Ñ', 'Ò', 'Ó', 'Ô', 'Õ', 'Ö', 'Ø', 'Ù', 'Ú', 'Û', 'Ü', 'Ý', 'ß', 'à', 'á', 'â', 'ã', 'ä', 'å', 'æ', 'ç', 'è', 'é', 'ê', 'ë', 'ì', 'í', 'î', 'ï', 'ñ', 'ò', 'ó', 'ô', 'õ', 'ö', 'ø', 'ù', 'ú', 'û', 'ü', 'ý', 'ÿ', 'A', 'a', 'A', 'a', 'A', 'a', 'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'Ð', 'd', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g', 'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', '?', '?', 'J', 'j', 'K', 'k', 'L', 'l', 'L', 'l', 'L', 'l', '?', '?', 'L', 'l', 'N', 'n', 'N', 'n', 'N', 'n', '?', 'O', 'o', 'O', 'o', 'O', 'o', 'Œ', 'œ', 'R', 'r', 'R', 'r', 'R', 'r', 'S', 's', 'S', 's', 'S', 's', 'Š', 'š', 'T', 't', 'T', 't', 'T', 't', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w', 'Y', 'y', 'Ÿ', 'Z', 'z', 'Z', 'z', 'Ž', 'ž', '?', 'ƒ', 'O', 'o', 'U', 'u', 'A', 'a', 'I', 'i', 'O', 'o', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', '?', '?', '?', '?', '?', '?'];
var b = ['A', 'A', 'A', 'A', 'A', 'A', 'AE', 'C', 'E', 'E', 'E', 'E', 'I', 'I', 'I', 'I', 'D', 'N', 'O', 'O', 'O', 'O', 'O', 'O', 'U', 'U', 'U', 'U', 'Y', 's', 'a', 'a', 'a', 'a', 'a', 'a', 'ae', 'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i', 'n', 'o', 'o', 'o', 'o', 'o', 'o', 'u', 'u', 'u', 'u', 'y', 'y', 'A', 'a', 'A', 'a', 'A', 'a', 'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'D', 'd', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g', 'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'IJ', 'ij', 'J', 'j', 'K', 'k', 'L', 'l', 'L', 'l', 'L', 'l', 'L', 'l', 'l', 'l', 'N', 'n', 'N', 'n', 'N', 'n', 'n', 'O', 'o', 'O', 'o', 'O', 'o', 'OE', 'oe', 'R', 'r', 'R', 'r', 'R', 'r', 'S', 's', 'S', 's', 'S', 's', 'S', 's', 'T', 't', 'T', 't', 'T', 't', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w', 'Y', 'y', 'Y', 'Z', 'z', 'Z', 'z', 'Z', 'z', 's', 'f', 'O', 'o', 'U', 'u', 'A', 'a', 'I', 'i', 'O', 'o', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'A', 'a', 'AE', 'ae', 'O', 'o'];
return function (str) {
var i = a.length;
while (i--) str = str.replace(a[i], b[i]);
return str;
};
}());
And a slightly modified version, using a char-map instead of two arrays:
To compare these two methods I made a simple benchmark: http://jsperf.com/replace-foreign-characters
/**
* Normalise a string replacing foreign characters
*
* @param {String} str
* @return {String}
*/
var normalize = (function () {
var map = {
"À": "A",
"Á": "A",
"Â": "A",
"Ã": "A",
"Ä": "A",
"Å": "A",
"Æ": "AE",
"Ç": "C",
"È": "E",
"É": "E",
"Ê": "E",
"Ë": "E",
"Ì": "I",
"Í": "I",
"Î": "I",
"Ï": "I",
"Ð": "D",
"Ñ": "N",
"Ò": "O",
"Ó": "O",
"Ô": "O",
"Õ": "O",
"Ö": "O",
"Ø": "O",
"Ù": "U",
"Ú": "U",
"Û": "U",
"Ü": "U",
"Ý": "Y",
"ß": "s",
"à": "a",
"á": "a",
"â": "a",
"ã": "a",
"ä": "a",
"å": "a",
"æ": "ae",
"ç": "c",
"è": "e",
"é": "e",
"ê": "e",
"ë": "e",
"ì": "i",
"í": "i",
"î": "i",
"ï": "i",
"ñ": "n",
"ò": "o",
"ó": "o",
"ô": "o",
"õ": "o",
"ö": "o",
"ø": "o",
"ù": "u",
"ú": "u",
"û": "u",
"ü": "u",
"ý": "y",
"ÿ": "y",
"A": "A",
"a": "a",
"A": "A",
"a": "a",
"A": "A",
"a": "a",
"C": "C",
"c": "c",
"C": "C",
"c": "c",
"C": "C",
"c": "c",
"C": "C",
"c": "c",
"D": "D",
"d": "d",
"Ð": "D",
"d": "d",
"E": "E",
"e": "e",
"E": "E",
"e": "e",
"E": "E",
"e": "e",
"E": "E",
"e": "e",
"E": "E",
"e": "e",
"G": "G",
"g": "g",
"G": "G",
"g": "g",
"G": "G",
"g": "g",
"G": "G",
"g": "g",
"H": "H",
"h": "h",
"H": "H",
"h": "h",
"I": "I",
"i": "i",
"I": "I",
"i": "i",
"I": "I",
"i": "i",
"I": "I",
"i": "i",
"I": "I",
"i": "i",
"?": "IJ",
"?": "ij",
"J": "J",
"j": "j",
"K": "K",
"k": "k",
"L": "L",
"l": "l",
"L": "L",
"l": "l",
"L": "L",
"l": "l",
"?": "L",
"?": "l",
"L": "l",
"l": "l",
"N": "N",
"n": "n",
"N": "N",
"n": "n",
"N": "N",
"n": "n",
"?": "n",
"O": "O",
"o": "o",
"O": "O",
"o": "o",
"O": "O",
"o": "o",
"Œ": "OE",
"œ": "oe",
"R": "R",
"r": "r",
"R": "R",
"r": "r",
"R": "R",
"r": "r",
"S": "S",
"s": "s",
"S": "S",
"s": "s",
"S": "S",
"s": "s",
"Š": "S",
"š": "s",
"T": "T",
"t": "t",
"T": "T",
"t": "t",
"T": "T",
"t": "t",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"W": "W",
"w": "w",
"Y": "Y",
"y": "y",
"Ÿ": "Y",
"Z": "Z",
"z": "z",
"Z": "Z",
"z": "z",
"Ž": "Z",
"ž": "z",
"?": "s",
"ƒ": "f",
"O": "O",
"o": "o",
"U": "U",
"u": "u",
"A": "A",
"a": "a",
"I": "I",
"i": "i",
"O": "O",
"o": "o",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"U": "U",
"u": "u",
"?": "A",
"?": "a",
"?": "AE",
"?": "ae",
"?": "O",
"?": "o"
},
nonWord = /\W/g,
mapping = function (c) {
return map[c] || c;
};
return function (str) {
return str.replace(nonWord, mapping);
};
}());
How to access ssis package variables inside script component
I had the same problem as the OP except I remembered to declare the ReadOnlyVariables.
After some playing around, I discovered it was the name of my variable that was the issue. "File_Path" in SSIS somehow got converted to "FilePath". C# does not play nicely with underscores in variable names.
So to access the variable, I type
string fp = Variables.FilePath;
In the PreExecute() method of the Script Component.
How to compare two tables column by column in oracle
SELECT *
FROM (SELECT table_name, COUNT (*) cnt
FROM all_tab_columns
WHERE owner IN ('OWNER_A')
GROUP BY table_name) x,
(SELECT table_name, COUNT (*) cnt
FROM all_tab_columns
WHERE owner IN ('OWNER_B')
GROUP BY table_name) y
WHERE x.table_name = y.table_name AND x.cnt <> y.cnt;
Set equal width of columns in table layout in Android
Change android:stretchColumns value to *.
Value 0 means stretch the first column. Value 1 means stretch the second column and so on.
Value * means stretch all the columns.
Why are only final variables accessible in anonymous class?
You can create a class level variable to get returned value. I mean
class A {
int k = 0;
private void f(Button b, int a){
b.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
k = a * 5;
}
});
}
now you can get value of K and use it where you want.
Answer of your why is :
A local inner class instance is tied to Main class and can access the final local variables of its containing method. When the instance uses a final local of its containing method, the variable retains the value it held at the time of the instance's creation, even if the variable has gone out of scope (this is effectively Java's crude, limited version of closures).
Because a local inner class is neither the member of a class or package, it is not declared with an access level. (Be clear, however, that its own members have access levels like in a normal class.)
How to dynamically add elements to String array?
You cant add add items in string array more than its size, i'll suggest you to use ArrayList you can add items dynamically at run time in arrayList if you feel any problem you can freely ask
Check if a input box is empty
<input ng-model="somefield">
<span ng-show="!somefield.length">Please enter something!</span>
<span ng-show="somefield.length">Good boy!</span>
You could also use ng-hide="somefield.length" instead of ng-show="!somefield.length" if that reads more naturally for you.
A better alternative might be to really take advantage of the form abilities of Angular:
<form name="myform">
<input name="myfield" ng-model="somefield" ng-minlength="5" required>
<span ng-show="myform.myfield.$error.required">Please enter something!</span>
<span ng-show="!myform.myfield.$error.required">Good boy!</span>
</form>
When does a process get SIGABRT (signal 6)?
There's another simple cause in case of c++.
std::thread::~thread{
if((joinable ())
std::terminate ();
}
i.e. scope of thread ended but you forgot to call either
thread::join();
or
thread::detach();
open a url on click of ok button in android
No need for any Java or Kotlin code to make it a clickable link, now you just need to follow given below code. And you can also link text color change by using textColorLink.
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:autoLink="web"
android:textColorLink="@color/white"/>
Excel Macro : How can I get the timestamp in "yyyy-MM-dd hh:mm:ss" format?
Use the Format function.
Format(Date, "yyyy-mm-dd hh:MM:ss")
Setting font on NSAttributedString on UITextView disregards line spacing
I found your question because I was also fighting with NSAttributedString.
For me, the beginEditing and endEditing methods did the trick, like stated in Changing an Attributed String.
Apart from that, the lineSpacing is set with setLineSpacing on the paragraphStyle.
So you might want to try changing your code to:
NSString *string = @" Hello \n world";
attrString = [[NSMutableAttributedString alloc] initWithString:string];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle defaultParagraphStyle] mutableCopy];
[paragraphStyle setLineSpacing:20] // Or whatever (positive) value you like...
[attrSting beginEditing];
[attrString addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:20] range:NSMakeRange(0, string.length)];
[attrString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, string.length)];
[attrString endEditing];
mainTextView.attributedText = attrString;
Didn't test this exact code though, btw, but mine looks nearly the same.
EDIT:
Meanwhile, I've tested it, and, correct me if I'm wrong, the - beginEditing and - endEditing calls seem to be of quite an importance.
css label width not taking effect
I believe labels are inline, and so they don't take a width. Maybe try using "display: block" and going from there.
How could I put a border on my grid control in WPF?
I think your problem is that the margin should be specified in the border tag and not in the grid.
How to set up Spark on Windows?
Here are seven steps to install spark on windows 10 and run it from python:
Step 1: download the spark 2.2.0 tar (tape Archive) gz file to any folder F from this link - https://spark.apache.org/downloads.html. Unzip it and copy the unzipped folder to the desired folder A. Rename the spark-2.2.0-bin-hadoop2.7 folder to spark.
Let path to the spark folder be C:\Users\Desktop\A\spark
Step 2: download the hardoop 2.7.3 tar gz file to the same folder F from this link - https://www.apache.org/dyn/closer.cgi/hadoop/common/hadoop-2.7.3/hadoop-2.7.3.tar.gz. Unzip it and copy the unzipped folder to the same folder A. Rename the folder name from Hadoop-2.7.3.tar to hadoop. Let path to the hadoop folder be C:\Users\Desktop\A\hadoop
Step 3: Create a new notepad text file. Save this empty notepad file as winutils.exe (with Save as type: All files). Copy this O KB winutils.exe file to your bin folder in spark - C:\Users\Desktop\A\spark\bin
Step 4: Now, we have to add these folders to the System environment.
4a: Create a system variable (not user variable as user variable will inherit all the properties of the system variable) Variable name: SPARK_HOME Variable value: C:\Users\Desktop\A\spark
Find Path system variable and click edit. You will see multiple paths. Do not delete any of the paths. Add this variable value - ;C:\Users\Desktop\A\spark\bin
4b: Create a system variable
Variable name: HADOOP_HOME Variable value: C:\Users\Desktop\A\hadoop
Find Path system variable and click edit. Add this variable value - ;C:\Users\Desktop\A\hadoop\bin
4c: Create a system variable Variable name: JAVA_HOME Search Java in windows. Right click and click open file location. You will have to again right click on any one of the java files and click on open file location. You will be using the path of this folder. OR you can search for C:\Program Files\Java. My Java version installed on the system is jre1.8.0_131. Variable value: C:\Program Files\Java\jre1.8.0_131\bin
Find Path system variable and click edit. Add this variable value - ;C:\Program Files\Java\jre1.8.0_131\bin
Step 5: Open command prompt and go to your spark bin folder (type cd C:\Users\Desktop\A\spark\bin). Type spark-shell.
C:\Users\Desktop\A\spark\bin>spark-shell
It may take time and give some warnings. Finally, it will show welcome to spark version 2.2.0
Step 6: Type exit() or restart the command prompt and go the spark bin folder again. Type pyspark:
C:\Users\Desktop\A\spark\bin>pyspark
It will show some warnings and errors but ignore. It works.
Step 7: Your download is complete. If you want to directly run spark from python shell then: go to Scripts in your python folder and type
pip install findspark
in command prompt.
In python shell
import findspark
findspark.init()
import the necessary modules
from pyspark import SparkContext
from pyspark import SparkConf
If you would like to skip the steps for importing findspark and initializing it, then please follow the procedure given in importing pyspark in python shell
Delete files in subfolder using batch script
Use powershell inside your bat file
PowerShell Remove-Item c:\scripts\* -include *.txt -exclude *test* -force -recurse
You can also exclude from removing some specific folder or file:
PowerShell Remove-Item C:/* -Exclude WINDOWS,autoexec.bat -force -recurse
Change user-agent for Selenium web-driver
There is no way in Selenium to read the request or response headers. You could do it by instructing your browser to connect through a proxy that records this kind of information.
Setting the User Agent in Firefox
The usual way to change the user agent for Firefox is to set the variable "general.useragent.override" in your Firefox profile. Note that this is independent from Selenium.
You can direct Selenium to use a profile different from the default one, like this:
from selenium import webdriver
profile = webdriver.FirefoxProfile()
profile.set_preference("general.useragent.override", "whatever you want")
driver = webdriver.Firefox(profile)
Setting the User Agent in Chrome
With Chrome, what you want to do is use the user-agent command line option. Again, this is not a Selenium thing. You can invoke Chrome at the command line with chrome --user-agent=foo to set the agent to the value foo.
With Selenium you set it like this:
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
opts = Options()
opts.add_argument("user-agent=whatever you want")
driver = webdriver.Chrome(chrome_options=opts)
Both methods above were tested and found to work. I don't know about other browsers.
Getting the User Agent
Selenium does not have methods to query the user agent from an instance of WebDriver. Even in the case of Firefox, you cannot discover the default user agent by checking what general.useragent.override would be if not set to a custom value. (This setting does not exist before it is set to some value.)
Once the browser is started, however, you can get the user agent by executing:
agent = driver.execute_script("return navigator.userAgent")
The agent variable will contain the user agent.
Removing rounded corners from a <select> element in Chrome/Webkit
well i got the solution. hope it may help you :)
select{_x000D_
border-image: url(http://www.w3schools.com/cssref/border.png) 30 stretch;_x000D_
width: 120px;_x000D_
height: 36px;_x000D_
color: #999;_x000D_
}<select>_x000D_
<option value="1">Hi</option>_x000D_
<option value="2">Bye</option>_x000D_
</select>SimpleDateFormat returns 24-hour date: how to get 12-hour date?
Hi I tested below code that worked fine :
long timeInMillis = System.currentTimeMillis();
Calendar cal1 = Calendar.getInstance();
cal1.setTimeInMillis(timeInMillis);
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/mm/yyyy hh:mm:ss a");
dateFormat.format(cal1.getTime());
Oracle date function for the previous month
The trunc() function truncates a date to the specified time period; so trunc(sysdate,'mm') would return the beginning of the current month. You can then use the add_months() function to get the beginning of the previous month, something like this:
select count(distinct switch_id)
from [email protected]
where dealer_name = 'XXXX'
and creation_date >= add_months(trunc(sysdate,'mm'),-1)
and creation_date < trunc(sysdate, 'mm')
As a little side not you're not explicitly converting to a date in your original query. Always do this, either using a date literal, e.g. DATE 2012-08-31, or the to_date() function, for example to_date('2012-08-31','YYYY-MM-DD'). If you don't then you are bound to get this wrong at some point.
You would not use sysdate - 15 as this would provide the date 15 days before the current date, which does not seem to be what you are after. It would also include a time component as you are not using trunc().
Just as a little demonstration of what trunc(<date>,'mm') does:
select sysdate
, case when trunc(sysdate,'mm') > to_date('20120901 00:00:00','yyyymmdd hh24:mi:ss')
then 1 end as gt
, case when trunc(sysdate,'mm') < to_date('20120901 00:00:00','yyyymmdd hh24:mi:ss')
then 1 end as lt
, case when trunc(sysdate,'mm') = to_date('20120901 00:00:00','yyyymmdd hh24:mi:ss')
then 1 end as eq
from dual
;
SYSDATE GT LT EQ
----------------- ---------- ---------- ----------
20120911 19:58:51 1
PHP get domain name
Similar question has been asked in stackoverflow before.
See here: PHP $_SERVER['HTTP_HOST'] vs. $_SERVER['SERVER_NAME'], am I understanding the man pages correctly?
Also see this article: http://shiflett.org/blog/2006/mar/server-name-versus-http-host
Recommended using HTTP_HOST, and falling back on SERVER_NAME only if HTTP_HOST was not set. He said that SERVER_NAME could be unreliable on the server for a variety of reasons, including:
- no DNS support
- misconfigured
- behind load balancing software
forEach loop Java 8 for Map entry set
You can use the following code for your requirement
map.forEach((k,v)->System.out.println("Item : " + k + " Count : " + v));
How to represent empty char in Java Character class
In java there is nothing as empty character literal, in other words, '' has no meaning unlike "" which means a empty String literal
The closest you can go about representing empty character literal is through zero length char[], something like:
char[] cArr = {}; // cArr is a zero length array
char[] cArr = new char[0] // this does the same
If you refer to String class its default constructor creates a empty character sequence using new char[0]
Also, using Character.MIN_VALUE is not correct because it is not really empty character rather smallest value of type character.
I also don't like Character c = null; as a solution mainly because jvm will throw NPE if it tries to un-box it. Secondly, null is basically a reference to nothing w.r.t reference type and here we are dealing with primitive type which don't accept null as a possible value.
Assuming that in the string, say str, OP wants to replace all occurrences of a character, say 'x', with empty character '', then try using:
str.replace("x", "");
Why doesn't margin:auto center an image?
Because your image is an inline-block element. You could change it to a block-level element like this:
<img src="queuedError.jpg" style="margin:auto; width:200px;display:block" />
and it will be centered.
Which browsers support <script async="async" />?
The async support as specified by google is achieved using two parts:
using script on your page (the script is supplied by google) to write out a <script> tag to the DOM.
that script has async="true" attribute to signal to compatible browsers that it can continue rendering the page.
The first part works on browsers without support for <script async.. tags, allowing them to load async with a "hack" (although a pretty solid one), and also allows rendering the page without waiting for ga.js to be retrieved.
The second part only affects compatible browsers that understand the async html attribute
- FF 3.6+
- FF for Android All Versions
- IE 10+ (starting with preview 2)
- Chrome 8+
- Chrome For Android All versions
- Safari 5.0+
- iOS Safari 5.0+
- Android Browser 3.0+ (honeycomb on up)
- Opera 15.0+
- Opera Mobile 16.0+
- Opera Mini None (as of 8.0)
The "html5 proper" way to specify async is with a <script async src="...", not <script async="true". However, initially browsers did not support this syntax, nor did they support setting the script property on referenced elements. If you want this, the list changes:
- FF 4+
- IE 10+ (preview 2 and up)
- Chrome 12+
- Chrome For Android 32+
- Safari 5.1+
- No android versions
Making a Sass mixin with optional arguments
With [email protected] :
// declare
@mixin button( $bgcolor:blue ){
background:$bgcolor;
}
and use without value, button will be blue
//use
.my_button{
@include button();
}
and with value, button will be red
//use
.my_button{
@include button( red );
}
works with hexa too
jQuery: How to detect window width on the fly?
Below is what i did to hide some Id element when screen size is below 768px, and show up when is above 768px. It works great.
var screensize= $( window ).width();
if(screensize<=768){
if($('#column-d0f6e77c699556473e4ff2967e9c0251').length>0)
{
$('#column-d0f6e77c699556473e4ff2967e9c0251').css('display','none');
}
}
else{
if($('#column-d0f6e77c699556473e4ff2967e9c0251').length>0)
{
$('#column-d0f6e77c699556473e4ff2967e9c0251').removeAttr( "style" );
}
}
changething = function(screensize){
if(screensize<=768){
if($('#column-d0f6e77c699556473e4ff2967e9c0251').length>0)
{
$('#column-d0f6e77c699556473e4ff2967e9c0251').css('display','none');
}
}
else{
if($('#column-d0f6e77c699556473e4ff2967e9c0251').length>0)
{
$('#column-d0f6e77c699556473e4ff2967e9c0251').removeAttr( "style" );
}
}
}
$( window ).resize(function() {
var screensize= $( window ).width();
changething(screensize);
});
How do I create a new Git branch from an old commit?
git checkout -b NEW_BRANCH_NAME COMMIT_ID
This will create a new branch called 'NEW_BRANCH_NAME' and check it out.
("check out" means "to switch to the branch")
git branch NEW_BRANCH_NAME COMMIT_ID
This just creates the new branch without checking it out.
in the comments many people seem to prefer doing this in two steps. here's how to do so in two steps:
git checkout COMMIT_ID
# you are now in the "detached head" state
git checkout -b NEW_BRANCH_NAME
Programmatically go back to previous ViewController in Swift
Swift 3
I might be late in the answer but for swift 3 you can do it this way:
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.leftBarButtonItem = UIBarButtonItem(title: "< Back", style: .plain, target: self, action: #selector(backAction))
// Do any additional setup if required.
}
func backAction(){
//print("Back Button Clicked")
dismiss(animated: true, completion: nil)
}
How to rotate a 3D object on axis three.js?
I solved in this way:
I created the 'ObjectControls' module for ThreeJS that allows you to rotate a single OBJECT (or a Group), and not the SCENE.
Include the libary:
<script src="ObjectControls.js"></script>
Usage:
var controls = new ObjectControls(camera, renderer.domElement, yourMesh);
You can find here a live demo here: https://albertopiras.github.io/threeJS-object-controls/
Here is the repo: https://github.com/albertopiras/threeJS-object-controls.
How do I hide the PHP explode delimiter from submitted form results?
Instead of adding the line breaks with nl2br() and then removing the line breaks with explode(), try using the line break character '\r' or '\n' or '\r\n'.
<?php $options= file_get_contents("employees.txt"); $options=explode("\n",$options); // try \r as well. foreach ($options as $singleOption){ echo "<option value='".$singleOption."'>".$singleOption."</option>"; } ?> This could also fix the issue if the problem was due to Google Spreadsheets reading the line breaks.
How to generate all permutations of a list?
#!/usr/bin/env python
def perm(a, k=0):
if k == len(a):
print a
else:
for i in xrange(k, len(a)):
a[k], a[i] = a[i] ,a[k]
perm(a, k+1)
a[k], a[i] = a[i], a[k]
perm([1,2,3])
Output:
[1, 2, 3]
[1, 3, 2]
[2, 1, 3]
[2, 3, 1]
[3, 2, 1]
[3, 1, 2]
As I'm swapping the content of the list it's required a mutable sequence type as input. E.g. perm(list("ball")) will work and perm("ball") won't because you can't change a string.
This Python implementation is inspired by the algorithm presented in the book Computer Algorithms by Horowitz, Sahni and Rajasekeran.
How to convert php array to utf8?
You can send the array to this function:
function utf8_converter($array){
array_walk_recursive($array, function(&$item, $key){
if(!mb_detect_encoding($item, 'utf-8', true)){
$item = utf8_encode($item);
}
});
return $array;
}
It works for me.
pip install - locale.Error: unsupported locale setting
The root cause is: your environment variable LC_ALL is missing or invalid somehow
Short answer-
just run the following command:
$ export LC_ALL=C
If you keep getting the error in new terminal windows, add it at the bottom of your .bashrc file.
Long answer-
Here is my locale settings:
$ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_PAPER="C"
LC_NAME="C"
LC_ADDRESS="C"
LC_TELEPHONE="C"
LC_MEASUREMENT="C"
LC_IDENTIFICATION="C"
LC_ALL=C
Python2.7
$ uname -a
Linux debian 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u6 (2015-11-09) x86_64 GNU/Linux
$ python --version
Python 2.7.9
$ pip --version
pip 8.1.1 from /usr/local/lib/python2.7/dist-packages (python 2.7)
$ unset LC_ALL
$ pip install virtualenv
Traceback (most recent call last):
File "/usr/local/bin/pip", line 11, in <module>
sys.exit(main())
File "/usr/local/lib/python2.7/dist-packages/pip/__init__.py", line 215, in main
locale.setlocale(locale.LC_ALL, '')
File "/usr/lib/python2.7/locale.py", line 579, in setlocale
return _setlocale(category, locale)
locale.Error: unsupported locale setting
$ export LC_ALL=C
$ pip install virtualenv
Requirement already satisfied (use --upgrade to upgrade): virtualenv in /usr/local/lib/python2.7/dist-packages
Creating a daemon in Linux
Try using the daemon function:
#include <unistd.h>
int daemon(int nochdir, int noclose);
From the man page:
The daemon() function is for programs wishing to detach themselves from the controlling terminal and run in the background as system daemons.
If nochdir is zero, daemon() changes the calling process's current working directory to the root directory ("/"); otherwise, the current working directory is left unchanged.
If noclose is zero, daemon() redirects standard input, standard output and standard error to /dev/null; otherwise, no changes are made to these file descriptors.
How to prevent auto-closing of console after the execution of batch file
cmd /k cd C:\Projects.....
If you want your cmd opened at specific long location
Dynamic loading of images in WPF
Here is the extension method to load an image from URI:
public static BitmapImage GetBitmapImage(
this Uri imageAbsolutePath,
BitmapCacheOption bitmapCacheOption = BitmapCacheOption.Default)
{
BitmapImage image = new BitmapImage();
image.BeginInit();
image.CacheOption = bitmapCacheOption;
image.UriSource = imageAbsolutePath;
image.EndInit();
return image;
}
Sample of use:
Uri _imageUri = new Uri(imageAbsolutePath);
ImageXamlElement.Source = _imageUri.GetBitmapImage(BitmapCacheOption.OnLoad);
Simple as that!
Logging in Scala
After using slf4s and logula for a while, I wrote loglady, a simple logging trait wrapping slf4j.
It offers an API similar to that of Python's logging library, which makes the common cases (basic string, simple formatting) trivial and avoids formatting boilerplate.
How to push a new folder (containing other folders and files) to an existing git repo?
You need to git add my_project to stage your new folder. Then git add my_project/* to stage its contents. Then commit what you've staged using git commit and finally push your changes back to the source using git push origin master (I'm assuming you wish to push to the master branch).
In which conda environment is Jupyter executing?
Question 1: How can I know which conda environment is my jupyter notebook running on?
Launch your Anaconda Prompt and run the command
conda env listto list all the available conda environments.
You can clearly see that I've two different conda environments installed on my PC, with my currently active environment being root(Python 2.7), indicated by the asterisk(*) symbol ahead of the path.
Question 2: How can I launch jupyter from a new conda environment?
Now, to launch the desired conda environment, simply run
activate <environment name>. In this case,activate py36
For more info, check out this link and this previous Stack Overflow question..
How do you create a Swift Date object?
Swift doesn't have its own Date type, but you to use the existing Cocoa NSDate type, e.g:
class Date {
class func from(year: Int, month: Int, day: Int) -> Date {
let gregorianCalendar = NSCalendar(calendarIdentifier: .gregorian)!
var dateComponents = DateComponents()
dateComponents.year = year
dateComponents.month = month
dateComponents.day = day
let date = gregorianCalendar.date(from: dateComponents)!
return date
}
class func parse(_ string: String, format: String = "yyyy-MM-dd") -> Date {
let dateFormatter = DateFormatter()
dateFormatter.timeZone = NSTimeZone.default
dateFormatter.dateFormat = format
let date = dateFormatter.date(from: string)!
return date
}
}
Which you can use like:
var date = Date.parse("2014-05-20")
var date = Date.from(year: 2014, month: 05, day: 20)
Data was not saved: object references an unsaved transient instance - save the transient instance before flushing
It should be CascadeType.Merge, in that case it will update if the record already exists.
Is it not possible to stringify an Error using JSON.stringify?
None of the answers above seemed to properly serialize properties which are on the prototype of Error (because getOwnPropertyNames() does not include inherited properties). I was also not able to redefine the properties like one of the answers suggested.
This is the solution I came up with - it uses lodash but you could replace lodash with generic versions of those functions.
function recursivePropertyFinder(obj){
if( obj === Object.prototype){
return {};
}else{
return _.reduce(Object.getOwnPropertyNames(obj),
function copy(result, value, key) {
if( !_.isFunction(obj[value])){
if( _.isObject(obj[value])){
result[value] = recursivePropertyFinder(obj[value]);
}else{
result[value] = obj[value];
}
}
return result;
}, recursivePropertyFinder(Object.getPrototypeOf(obj)));
}
}
Error.prototype.toJSON = function(){
return recursivePropertyFinder(this);
}
Here's the test I did in Chrome:
var myError = Error('hello');
myError.causedBy = Error('error2');
myError.causedBy.causedBy = Error('error3');
myError.causedBy.causedBy.displayed = true;
JSON.stringify(myError);
{"name":"Error","message":"hello","stack":"Error: hello\n at <anonymous>:66:15","causedBy":{"name":"Error","message":"error2","stack":"Error: error2\n at <anonymous>:67:20","causedBy":{"name":"Error","message":"error3","stack":"Error: error3\n at <anonymous>:68:29","displayed":true}}}
How to fix "Root element is missing." when doing a Visual Studio (VS) Build?
I got same error. showing error Microsoft.Data.Entity could not loaded root element missing. When i delete that file from C:\Windows\Microsoft.NET\Framework\v4.0.30319 and again open my solution my problem was solved. Everything woks fine
Measuring the distance between two coordinates in PHP
Try this function out to calculate distance between to points of latitude and longitude
function calculateDistanceBetweenTwoPoints($latitudeOne='', $longitudeOne='', $latitudeTwo='', $longitudeTwo='',$distanceUnit ='',$round=false,$decimalPoints='')
{
if (empty($decimalPoints))
{
$decimalPoints = '3';
}
if (empty($distanceUnit)) {
$distanceUnit = 'KM';
}
$distanceUnit = strtolower($distanceUnit);
$pointDifference = $longitudeOne - $longitudeTwo;
$toSin = (sin(deg2rad($latitudeOne)) * sin(deg2rad($latitudeTwo))) + (cos(deg2rad($latitudeOne)) * cos(deg2rad($latitudeTwo)) * cos(deg2rad($pointDifference)));
$toAcos = acos($toSin);
$toRad2Deg = rad2deg($toAcos);
$toMiles = $toRad2Deg * 60 * 1.1515;
$toKilometers = $toMiles * 1.609344;
$toNauticalMiles = $toMiles * 0.8684;
$toMeters = $toKilometers * 1000;
$toFeets = $toMiles * 5280;
$toYards = $toFeets / 3;
switch (strtoupper($distanceUnit))
{
case 'ML'://miles
$toMiles = ($round == true ? round($toMiles) : round($toMiles, $decimalPoints));
return $toMiles;
break;
case 'KM'://Kilometers
$toKilometers = ($round == true ? round($toKilometers) : round($toKilometers, $decimalPoints));
return $toKilometers;
break;
case 'MT'://Meters
$toMeters = ($round == true ? round($toMeters) : round($toMeters, $decimalPoints));
return $toMeters;
break;
case 'FT'://feets
$toFeets = ($round == true ? round($toFeets) : round($toFeets, $decimalPoints));
return $toFeets;
break;
case 'YD'://yards
$toYards = ($round == true ? round($toYards) : round($toYards, $decimalPoints));
return $toYards;
break;
case 'NM'://Nautical miles
$toNauticalMiles = ($round == true ? round($toNauticalMiles) : round($toNauticalMiles, $decimalPoints));
return $toNauticalMiles;
break;
}
}
Then use the fucntion as
echo calculateDistanceBetweenTwoPoints('11.657740','77.766270','11.074820','77.002160','ML',true,5);
Hope it helps
JSON.Net Self referencing loop detected
for asp.net core 3.1.3 this worked for me
services.AddControllers().AddNewtonsoftJson(opt=>{
opt.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
});
Finding an item in a List<> using C#
For .NET 2.0:
list.Find(delegate(Item i) { return i.Property == someValue; });
How can I convert an Int to a CString?
If you want something more similar to your example try _itot_s. On Microsoft compilers _itot_s points to _itoa_s or _itow_s depending on your Unicode setting:
CString str;
_itot_s( 15, str.GetBufferSetLength( 40 ), 40, 10 );
str.ReleaseBuffer();
it should be slightly faster since it doesn't need to parse an input format.
How do I free memory in C?
You actually can't manually "free" memory in C, in the sense that the memory is released from the process back to the OS ... when you call malloc(), the underlying libc-runtime will request from the OS a memory region. On Linux, this may be done though a relatively "heavy" call like mmap(). Once this memory region is mapped to your program, there is a linked-list setup called the "free store" that manages this allocated memory region. When you call malloc(), it quickly looks though the free-store for a free block of memory at the size requested. It then adjusts the linked list to reflect that there has been a chunk of memory taken out of the originally allocated memory pool. When you call free() the memory block is placed back in the free-store as a linked-list node that indicates its an available chunk of memory.
If you request more memory than what is located in the free-store, the libc-runtime will again request more memory from the OS up to the limit of the OS's ability to allocate memory for running processes. When you free memory though, it's not returned back to the OS ... it's typically recycled back into the free-store where it can be used again by another call to malloc(). Thus, if you make a lot of calls to malloc() and free() with varying memory size requests, it could, in theory, cause a condition called "memory fragmentation", where there is enough space in the free-store to allocate your requested memory block, but not enough contiguous space for the size of the block you've requested. Thus the call to malloc() fails, and you're effectively "out-of-memory" even though there may be plenty of memory available as a total amount of bytes in the free-store.
How can I make a UITextField move up when the keyboard is present - on starting to edit?
I wrap everything in one class. Just call these lines of code when your viewcontroller is loaded:
- (void)viewDidLoad {
[super viewDidLoad];
KeyboardInsetScrollView *injectView = [[KeyboardInsetScrollView alloc] init];
[injectView injectToView:self.view withRootView:self.view];
}
Here is link of sample project:
https://github.com/caohuuloc/KeyboardInsetScrollView
MongoDB: exception in initAndListen: 20 Attempted to create a lock file on a read-only directory: /data/db, terminating
Check if SElinux is enabled. If it is in enforcing mode just try with permissive mode. In case that helps you should create SElinux policies for mongodb.
You can try with audit2allow - check https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security-enhanced_linux/sect-security-enhanced_linux-fixing_problems-allowing_access_audit2allow
What is the point of "final class" in Java?
Final classes cannot be extended. So if you want a class to behave a certain way and don't someone to override the methods (with possibly less efficient and more malicious code), you can declare the whole class as final or specific methods which you don't want to be changed.
Since declaring a class does not prevent a class from being instantiated, it does not mean it will stop the class from having the characteristics of an object. It's just that you will have to stick to the methods just the way they are declared in the class.
How to make a page redirect using JavaScript?
Use:
window.location = "http://my.url.here";
Here's some quick-n-dirty code that uses jQuery to do what you want. I highly recommend using jQuery. It'll make things a lot more easier for you, especially since you're new to JavaScript.
<select id = "pricingOptions" name = "pricingOptions">
<option value = "500">Option A</option>
<option value = "1000">Option B</option>
</select>
<script type = "text/javascript" language = "javascript">
jQuery(document).ready(function() {
jQuery("#pricingOptions").change(function() {
if(this.options[this.selectedIndex].value == "500") {
window.location = "http://example.com/foo.php?option=500";
}
});
});
</script>
How to change the color of the axis, ticks and labels for a plot in matplotlib
As a quick example (using a slightly cleaner method than the potentially duplicate question):
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(range(10))
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
ax.spines['bottom'].set_color('red')
ax.spines['top'].set_color('red')
ax.xaxis.label.set_color('red')
ax.tick_params(axis='x', colors='red')
plt.show()
Alternatively
[t.set_color('red') for t in ax.xaxis.get_ticklines()]
[t.set_color('red') for t in ax.xaxis.get_ticklabels()]
java.io.FileNotFoundException: /storage/emulated/0/New file.txt: open failed: EACCES (Permission denied)
For SDK 29 :
String str1 = "";
folder1 = new File(String.valueOf(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES)));
if (folder1.exists()) {str1 = folder1.toString() + File.separator;}
public static void createTextFile(String sBody, String FileName, String Where) {
try {
File gpxfile = new File(Where, FileName);
FileWriter writer = new FileWriter(gpxfile);
writer.append(sBody);
writer.flush();
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Then you can save your file like this :
createTextFile("This is Content","file.txt",str1);
Enable 'xp_cmdshell' SQL Server
For me, the only way on SQL 2008 R2 was this :
EXEC sp_configure 'Show Advanced Options', 1
RECONFIGURE **WITH OVERRIDE**
EXEC sp_configure 'xp_cmdshell', 1
RECONFIGURE **WITH OVERRIDE**
Subscripts in plots in R
Another example, expression works for negative superscripts without the need for quotes around the negative number:
title(xlab=expression("Nitrate Loading in kg ha"^-1*"yr"^-1))
and you only need the * to separate sections as mentioned above (when you write a superscript or subscript and need to add more text to the expression after).
Javascript isnull
You could try this:
if(typeof(results) == "undefined") {
return 0;
} else {
return results[1] || 0;
}
ReferenceError: Invalid left-hand side in assignment
Common reasons for the error:
- use of assignment (
=) instead of equality (==/===) - assigning to result of function
foo() = 42instead of passing arguments (foo(42)) - simply missing member names (i.e. assuming some default selection) :
getFoo() = 42instead ofgetFoo().theAnswer = 42or array indexinggetArray() = 42instead ofgetArray()[0]= 42
In this particular case you want to use == (or better === - What exactly is Type Coercion in Javascript?) to check for equality (like if(one === "rock" && two === "rock"), but it the actual reason you are getting the error is trickier.
The reason for the error is Operator precedence. In particular we are looking for && (precedence 6) and = (precedence 3).
Let's put braces in the expression according to priority - && is higher than = so it is executed first similar how one would do 3+4*5+6 as 3+(4*5)+6:
if(one= ("rock" && two) = "rock"){...
Now we have expression similar to multiple assignments like a = b = 42 which due to right-to-left associativity executed as a = (b = 42). So adding more braces:
if(one= ( ("rock" && two) = "rock" ) ){...
Finally we arrived to actual problem: ("rock" && two) can't be evaluated to l-value that can be assigned to (in this particular case it will be value of two as truthy).
Note that if you'd use braces to match perceived priority surrounding each "equality" with braces you get no errors. Obviously that also producing different result than you'd expect - changes value of both variables and than do && on two strings "rock" && "rock" resulting in "rock" (which in turn is truthy) all the time due to behavior of logial &&:
if((one = "rock") && (two = "rock"))
{
// always executed, both one and two are set to "rock"
...
}
For even more details on the error and other cases when it can happen - see specification:
LeftHandSideExpression = AssignmentExpression
...
Throw a SyntaxError exception if the following conditions are all true:
...
IsStrictReference(lref) is true
and The Reference Specification Type explaining IsStrictReference:
... function calls are permitted to return references. This possibility is admitted purely for the sake of host objects. No built-in ECMAScript function defined by this specification returns a reference and there is no provision for a user-defined function to return a reference...
The server principal is not able to access the database under the current security context in SQL Server MS 2012
We had the same error even though the user was properly mapped to the login.
After trying to delete the user it was discovered that a few SPs contained "with execute as" that user.
The issue was solved by dropping those SPs, dropping the user, recreating the user linked to login, and recreating the SPs.
Possibly it got in this state from restoring from backup (during a time when the related login didn't exist) or bulk schema syncing (if its possible to create an SP with execute as even though the user doesn't exist. Could also have been related to this answer.
Calling a method every x minutes
Example of using a Timer:
using System;
using System.Timers;
static void Main(string[] args)
{
Timer t = new Timer(TimeSpan.FromMinutes(5).TotalMilliseconds); // Set the time (5 mins in this case)
t.AutoReset = true;
t.Elapsed += new System.Timers.ElapsedEventHandler(your_method);
t.Start();
}
// This method is called every 5 mins
private static void your_method(object sender, ElapsedEventArgs e)
{
Console.WriteLine("...");
}
How does one convert a HashMap to a List in Java?
If you wanna maintain the same order in your list, say: your Map looks like:
map.put(1, "msg1")
map.put(2, "msg2")
map.put(3, "msg3")
and you want your list looks like
["msg1", "msg2", "msg3"] // same order as the map
you will have to iterate through the Map:
// sort your map based on key, otherwise you will get IndexOutofBoundException
Map<String, String> treeMap = new TreeMap<String, String>(map)
List<String> list = new List<String>();
for (treeMap.Entry<Integer, String> entry : treeMap.entrySet()) {
list.add(entry.getKey(), entry.getValue());
}
jQuery show for 5 seconds then hide
You can use .delay() before an animation, like this:
$("#myElem").show().delay(5000).fadeOut();
If it's not an animation, use setTimeout() directly, like this:
$("#myElem").show();
setTimeout(function() { $("#myElem").hide(); }, 5000);
You do the second because .hide() wouldn't normally be on the animation (fx) queue without a duration, it's just an instant effect.
Or, another option is to use .delay() and .queue() yourself, like this:
$("#myElem").show().delay(5000).queue(function(n) {
$(this).hide(); n();
});
how to get current location in google map android
public void getMyLocation() {
// create class object
gps = new GPSTracker(HomeActivity.this);
// check if GPS enabled
if (gps.canGetLocation()) {
latitude = gps.getLatitude();
longitude = gps.getLongitude();
Geocoder geocoder;
List<Address> addresses;
geocoder = new Geocoder(this, Locale.getDefault());
try {
addresses = geocoder.getFromLocation(latitude, longitude, 1);
postalCode = addresses.get(0).getPostalCode();
city = addresses.get(0).getLocality();
address = addresses.get(0).getAddressLine(0);
state = addresses.get(0).getAdminArea();
country = addresses.get(0).getCountryName();
knownName = addresses.get(0).getFeatureName();
Log.e("Location",postalCode+" "+city+" "+address+" "+state+" "+knownName);
} catch (IOException e) {
e.printStackTrace();
}
} else {
gps.showSettingsAlert();
}
}
Check if a string contains a number
You can use a combination of any and str.isdigit:
def num_there(s):
return any(i.isdigit() for i in s)
The function will return True if a digit exists in the string, otherwise False.
Demo:
>>> king = 'I shall have 3 cakes'
>>> num_there(king)
True
>>> servant = 'I do not have any cakes'
>>> num_there(servant)
False
Display / print all rows of a tibble (tbl_df)
You can use as.data.frame or print.data.frame.
If you want this to be the default, you can change the value of the dplyr.print_max option.
options(dplyr.print_max = 1e9)
Is it safe to expose Firebase apiKey to the public?
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains. One can read more about it on Firebase Security rules
How to throw an exception in C?
Implementing exceptions in c by Eric Roberts
Chapter 4 of C Interfaces and Implementations by Hanson.
A Discipline of Error Handling by Doug Moen
Implementing Exceptions in C (details the article of E Roberts)
How to print colored text to the terminal?
Stupidly simple, based on joeld's answer:
class PrintInColor:
RED = '\033[91m'
GREEN = '\033[92m'
YELLOW = '\033[93m'
LIGHT_PURPLE = '\033[94m'
PURPLE = '\033[95m'
END = '\033[0m'
@classmethod
def red(cls, s, **kwargs):
print(cls.RED + s + cls.END, **kwargs)
@classmethod
def green(cls, s, **kwargs):
print(cls.GREEN + s + cls.END, **kwargs)
@classmethod
def yellow(cls, s, **kwargs):
print(cls.YELLOW + s + cls.END, **kwargs)
@classmethod
def lightPurple(cls, s, **kwargs):
print(cls.LIGHT_PURPLE + s + cls.END, **kwargs)
@classmethod
def purple(cls, s, **kwargs):
print(cls.PURPLE + s + cls.END, **kwargs)
Then just
PrintInColor.red('hello', end=' ')
PrintInColor.green('world')
Using lodash to compare jagged arrays (items existence without order)
Edit: I missed the multi-dimensional aspect of this question, so I'm leaving this here in case it helps people compare one-dimensional arrays
It's an old question, but I was having issues with the speed of using .sort() or sortBy(), so I used this instead:
function arraysContainSameStrings(array1: string[], array2: string[]): boolean {
return (
array1.length === array2.length &&
array1.every((str) => array2.includes(str)) &&
array2.every((str) => array1.includes(str))
)
}
It was intended to fail fast, and for my purposes works fine.
How to loop over grouped Pandas dataframe?
df.groupby('l_customer_id_i').agg(lambda x: ','.join(x)) does already return a dataframe, so you cannot loop over the groups anymore.
In general:
df.groupby(...)returns aGroupByobject (a DataFrameGroupBy or SeriesGroupBy), and with this, you can iterate through the groups (as explained in the docs here). You can do something like:grouped = df.groupby('A') for name, group in grouped: ...When you apply a function on the groupby, in your example
df.groupby(...).agg(...)(but this can also betransform,apply,mean, ...), you combine the result of applying the function to the different groups together in one dataframe (the apply and combine step of the 'split-apply-combine' paradigm of groupby). So the result of this will always be again a DataFrame (or a Series depending on the applied function).
How to unescape HTML character entities in Java?
This did the job for me,
import org.apache.commons.lang.StringEscapeUtils;
...
String decodedXML= StringEscapeUtils.unescapeHtml(encodedXML);
or
import org.apache.commons.lang3.StringEscapeUtils;
...
String decodedXML= StringEscapeUtils.unescapeHtml4(encodedXML);
I guess its always better to use the lang3 for obvious reasons.
Hope this helps :)
C# List<string> to string with delimiter
You can use String.Join. If you have a List<string> then you can call ToArray first:
List<string> names = new List<string>() { "John", "Anna", "Monica" };
var result = String.Join(", ", names.ToArray());
In .NET 4 you don't need the ToArray anymore, since there is an overload of String.Join that takes an IEnumerable<string>.
Results:
John, Anna, Monica
How to create a DataTable in C# and how to add rows?
Here's the code:
DataTable dt = new DataTable();
dt.Clear();
dt.Columns.Add("Name");
dt.Columns.Add("Marks");
DataRow _ravi = dt.NewRow();
_ravi["Name"] = "ravi";
_ravi["Marks"] = "500";
dt.Rows.Add(_ravi);
To see the structure, or rather I'd rephrase it as schema, you can export it to an XML file by doing the following.
To export only the schema/structure, do:
dt.WriteXMLSchema("dtSchemaOrStructure.xml");
Additionally, you can also export your data:
dt.WriteXML("dtDataxml");
DateTime to javascript date
I know this is a little late, but here's the solution I had to come up with for handling dates when you want to be timezone independent. Essentially it involves converting everything to UTC.
From Javascript to Server:
Send out dates as epoch values with the timezone offset removed.
var d = new Date(2015,0,1) // Jan 1, 2015
// Ajax Request to server ...
$.ajax({
url: '/target',
params: { date: d.getTime() - (d.getTimezoneOffset() * 60 * 1000) }
});
The server then recieves 1420070400000 as the date epoch.
On the Server side, convert that epoch value to a datetime object:
DateTime d = new DateTime(1970, 1, 1, 0, 0, 0).AddMilliseconds(epoch);
At this point the date is just the date/time provided by the user as they provided it. Effectively it is UTC.
Going the other way:
When the server pulls data from the database, presumably in UTC, get the difference as an epoch (making sure that both date objects are either local or UTC):
long ms = (long)utcDate.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds;
or
long ms = (long)localDate.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Local)).TotalMilliseconds;
When javascript receives this value, create a new date object. However, this date object is going to be assumed local time, so you need to offset it by the current timezone:
var epochValue = 1420070400000 // value pulled from server.
var utcDateVal = new Date(epochValue);
var actualDate = new Date(utcDateVal.getTime() + (utcDateVal.getTimezoneOffset() * 60 * 1000))
console.log(utcDateVal); // Wed Dec 31 2014 19:00:00 GMT-0500 (Eastern Standard Time)
console.log(actualDate); // Thu Jan 01 2015 00:00:00 GMT-0500 (Eastern Standard Time)
As far as I know, this should work for any time zone where you need to display dates that are timezone independent.
What does the @ symbol before a variable name mean in C#?
The @ symbol serves 2 purposes in C#:
Firstly, it allows you to use a reserved keyword as a variable like this:
int @int = 15;
The second option lets you specify a string without having to escape any characters. For instance the '\' character is an escape character so typically you would need to do this:
var myString = "c:\\myfolder\\myfile.txt"
alternatively you can do this:
var myString = @"c:\myFolder\myfile.txt"
PHP Redirect to another page after form submit
Whenever you want to redirect, send the headers:
header("Location: http://www.example.com/");
Remember you cant send data to the client before that, though.
Check if a property exists in a class
If you are binding like I was:
<%# Container.DataItem.GetType().GetProperty("Property1") != null ? DataBinder.Eval(Container.DataItem, "Property1") : DataBinder.Eval(Container.DataItem, "Property2") %>
How to use jQuery to show/hide divs based on radio button selection?
You can use jQuery’s show() and hide() methods. Like below:
JQuery:
$(document).ready(function(){
$('input[type="radio"]').click(function(){
var val = $(this).attr("value");
var target = $("." + val);
$(".msg").not(target).hide();
$(target).show();
});
});
HTML:
<input type="radio" name="color" value="yellow"> Yellow
<input type="radio" name="color" value="red"> Red
<input type="radio" name="color" value="green"> Green
<div class="yellow msg">You have selected Yellow</div>
<div class="red msg">You have selected Red</div>
<div class="green msg">You have selected Green</div>
Here is an example: Show/hide DIV based on Radio Button click
How do I configure HikariCP in my Spring Boot app in my application.properties files?
This will help anyone who wants to configure hikaricp for their application with spring auto configuration. For my project, im using spring boot 2 with hikaricp as the JDBC connection pool and mysql as the database. One thing I didn't see in other answers was the data-source-properties which can be used to set various properties that are not available at the spring.datasource.hikari.* path. This is equivalent to using the HikariConfig class. To configure the datasource and hikaricp connection pool for mysql specific properties I used the spring auto configure annotation and the following properties in the application.yml file.
Place @EnableAutoConfiguration on one of your configuration bean files.
application.yml file can look like this.
spring:
datasource:
url: 'jdbc:mysql://127.0.0.1:3306/DATABASE?autoReconnect=true&useSSL=false'
username: user_name
password: password
hikari:
maximum-pool-size: 20
data-source-properties:
cachePrepStmts: true
prepStmtCacheSize: 250
prepStmtCacheSqlLimit: 2048
useServerPrepStmts: true
useLocalSessionState: true
rewriteBatchedStatements: true
cacheResultSetMetadata: true
cacheServerConfiguration: true
elideSetAutoCommits: true
maintainTimeStats: false
How do I move files in node.js?
The fs-extra module allows you to do this with it's move() method. I already implemented it and it works well if you want to completely move a file from one directory to another - ie. removing the file from the source directory. Should work for most basic cases.
var fs = require('fs-extra')
fs.move('/tmp/somefile', '/tmp/does/not/exist/yet/somefile', function (err) {
if (err) return console.error(err)
console.log("success!")
})
How exactly does the android:onClick XML attribute differ from setOnClickListener?
Be careful, although android:onClick XML seems to be a convenient way to handle click, the setOnClickListener implementation do something additional than adding the onClickListener. Indeed, it put the view property clickable to true.
While it's might not be a problem on most Android implementations, according to the phone constructor, button is always default to clickable = true but other constructors on some phone model might have a default clickable = false on non Button views.
So setting the XML is not enough, you have to think all the time to add android:clickable="true" on non button, and if you have a device where the default is clickable = true and you forget even once to put this XML attribute, you won't notice the problem at runtime but will get the feedback on the market when it will be in the hands of your customers !
In addition, we can never be sure about how proguard will obfuscate and rename XML attributes and class method, so not 100% safe that they will never have a bug one day.
So if you never want to have trouble and never think about it, it's better to use setOnClickListener or libraries like ButterKnife with annotation @OnClick(R.id.button)
find first sequence item that matches a criterion
a=[100,200,300,400,500]
def search(b):
try:
k=a.index(b)
return a[k]
except ValueError:
return 'not found'
print(search(500))
it'll return the object if found else it'll return "not found"
Color Tint UIButton Image
As of iOS 7, there is a new method on UIImage to specify the rendering mode. Using the rendering mode UIImageRenderingModeAlwaysTemplate will allow the image color to be controlled by the button's tint color.
Objective-C
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [[UIImage imageNamed:@"image_name"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[button setImage:image forState:UIControlStateNormal];
button.tintColor = [UIColor redColor];
Swift
let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red
.htaccess 301 redirect of single page
It will redirect your store page to your contact page
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
Redirect 301 /storepage /contactpage
</IfModule>
Viewing root access files/folders of android on windows
If you have android, you can install free app on phone (Wifi file Transfer) and enable ssl, port and other options for access and send data in both directions just start application and write in pc browser phone ip and port. enjoy!
Semaphore vs. Monitors - what's the difference?
Semaphore :
Using a counter or flag to control access some shared resources in a concurrent system, implies use of Semaphore.
Example:
- A counter to allow only 50 Passengers to acquire the 50 seats (Shared resource) of any Theatre/Bus/Train/Fun ride/Classroom. And to allow a new Passenger only if someone vacates a seat.
- A binary flag indicating the free/occupied status of any Bathroom.
- Traffic lights are good example of flags. They control flow by regulating passage of vehicles on Roads (Shared resource)
Flags only reveal the current state of Resource, no count or any other information on the waiting or running objects on the resource.
Monitor :
A Monitor synchronizes access to an Object by communicating with threads interested in the object, asking them to acquire access or wait for some condition to become true.
Example:
- A Father may acts as a monitor for her daughter, allowing her to date only one guy at a time.
- A school teacher using baton to allow only one child to speak in the class.
- Lastly a technical one, transactions (via threads) on an Account object synchronized to maintain integrity.
How to send HTML-formatted email?
Setting isBodyHtml to true allows you to use HTML tags in the message body:
msg = new MailMessage("[email protected]",
"[email protected]", "Message from PSSP System",
"This email sent by the PSSP system<br />" +
"<b>this is bold text!</b>");
msg.IsBodyHtml = true;
What's the difference between process.cwd() vs __dirname?
Knowing the scope of each can make things easier to remember.
process is node's global object, and .cwd() returns where node is running.
__dirname is module's property, and represents the file path of the module. In node, one module resides in one file.
Similarly, __filename is another module's property, which holds the file name of the module.
What's the difference between deadlock and livelock?
Imagine you've thread A and thread B. They are both synchronised on the same object and inside this block there's a global variable they are both updating;
static boolean commonVar = false;
Object lock = new Object;
...
void threadAMethod(){
...
while(commonVar == false){
synchornized(lock){
...
commonVar = true
}
}
}
void threadBMethod(){
...
while(commonVar == true){
synchornized(lock){
...
commonVar = false
}
}
}
So, when thread A enters in the while loop and holds the lock, it does what it has to do and set the commonVar to true. Then thread B comes in, enters in the while loop and since commonVar is true now, it is be able to hold the lock. It does so, executes the synchronised block, and sets commonVar back to false. Now, thread A again gets it's new CPU window, it was about to quit the while loop but thread B has just set it back to false, so the cycle repeats over again. Threads do something (so they're not blocked in the traditional sense) but for pretty much nothing.
It maybe also nice to mention that livelock does not necessarily have to appear here. I'm assuming that the scheduler favours the other thread once the synchronised block finish executing. Most of the time, I think it's a hard-to-hit expectation and depends on many things happening under the hood.
Get generic type of class at runtime
This is my solution:
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
public class GenericClass<T extends String> {
public static void main(String[] args) {
for (TypeVariable typeParam : GenericClass.class.getTypeParameters()) {
System.out.println(typeParam.getName());
for (Type bound : typeParam.getBounds()) {
System.out.println(bound);
}
}
}
}
How do I update Node.js?
All platforms (Windows, Mac & Linux)
Updated Feb 2021
Just go to nodejs.org and use the latest installer.
That's it folks. It used to be more complex and people used different kinds of packages and strategies to manage it. But things have changed for the better.
htaccess <Directory> deny from all
You cannot use the Directory directive in .htaccess. However if you create a .htaccess file in the /system directory and place the following in it, you will get the same result
#place this in /system/.htaccess as you had before
deny from all
How to vertically align label and input in Bootstrap 3?
This works perfectly for me in Bootstrap 4.
<div class="form-row align-items-center">
<div class="col-md-2">
<label for="FirstName" style="margin-bottom:0rem !important;">First Name</label>
</div>
<div class="col-md-10">
<input type="text" id="FirstName" name="FirstName" class="form-control" val=""/>
/div>
</div>
SQL (MySQL) vs NoSQL (CouchDB)
One of the best options is to go for MongoDB(NOSql dB) that supports scalability.Stores large amounts of data nothing but bigdata in the form of documents unlike rows and tables in sql.This is fasters that follows sharding of the data.Uses replicasets to ensure data guarantee that maintains multiple servers having primary db server as the base. Language independent. Flexible to use
VERR_VMX_MSR_VMXON_DISABLED when starting an image from Oracle virtual box
Which version VirtualBox do you use? I found the same problem and when use update latest version on my X64 win7 machine VirtualBox-4.3.4-91027-Win But I uninstall it and back to VirtualBox-4.2.18-88781-Win
It works well, try it until Oracle fix it.
How do I change TextView Value inside Java Code?
First we need to find a Button:
Button mButton = (Button) findViewById(R.id.my_button);
After that, you must implement View.OnClickListener and there you should find the TextView and execute the method setText:
mButton.setOnClickListener(new View.OnClickListener {
public void onClick(View v) {
final TextView mTextView = (TextView) findViewById(R.id.my_text_view);
mTextView.setText("Some Text");
}
});
Convert datetime object to a String of date only in Python
If you looking for a simple way of datetime to string conversion and can omit the format. You can convert datetime object to str and then use array slicing.
In [1]: from datetime import datetime
In [2]: now = datetime.now()
In [3]: str(now)
Out[3]: '2019-04-26 18:03:50.941332'
In [5]: str(now)[:10]
Out[5]: '2019-04-26'
In [6]: str(now)[:19]
Out[6]: '2019-04-26 18:03:50'
But note the following thing. If other solutions will rise an AttributeError when the variable is None in this case you will receive a 'None' string.
In [9]: str(None)[:19]
Out[9]: 'None'
How to remove all null elements from a ArrayList or String Array?
As of 2015, this is the best way (Java 8):
tourists.removeIf(Objects::isNull);
Note: This code will throw java.lang.UnsupportedOperationException for fixed-size lists (such as created with Arrays.asList), including immutable lists.
How can I label points in this scatterplot?
You should use labels attribute inside plot function and the value of this attribute should be the vector containing the values that you want for each point to have.
How to use ng-repeat without an html element
I would like to just comment, but my reputation is still lacking. So i'm adding another solution which solves the problem as well. I would really like to refute the statement made by @bmoeskau that solving this problem requires a 'hacky at best' solution, and since this came up recently in a discussion even though this post is 2 years old, i'd like to add my own two cents:
As @btford has pointed out, you seem to be trying to turn a recursive structure into a list, so you should flatten that structure into a list first. His solution does that, but there is an opinion that calling the function inside the template is inelegant. if that is true (honestly, i dont know) wouldnt that just require executing the function in the controller rather than the directive?
either way, your html requires a list, so the scope that renders it should have that list to work with. you simply have to flatten the structure inside your controller. once you have a $scope.rows array, you can generate the table with a single, simple ng-repeat. No hacking, no inelegance, simply the way it was designed to work.
Angulars directives aren't lacking functionality. They simply force you to write valid html. A colleague of mine had a similar issue, citing @bmoeskau in support of criticism over angulars templating/rendering features. When looking at the exact problem, it turned out he simply wanted to generate an open-tag, then a close tag somewhere else, etc.. just like in the good old days when we would concat our html from strings.. right? no.
as for flattening the structure into a list, here's another solution:
// assume the following structure
var structure = [
{
name: 'item1', subitems: [
{
name: 'item2', subitems: [
],
}
],
}
];
var flattened = structure.reduce((function(prop,resultprop){
var f = function(p,c,i,a){
p.push(c[resultprop]);
if (c[prop] && c[prop].length > 0 )
p = c[prop].reduce(f,p);
return p;
}
return f;
})('subitems','name'),[]);
// flattened now is a list: ['item1', 'item2']
this will work for any tree-like structure that has sub items. If you want the whole item instead of a property, you can shorten the flattening function even more.
hope that helps.
What is the best way to modify a list in a 'foreach' loop?
As mentioned, but with a code sample:
foreach(var item in collection.ToArray())
collection.Add(new Item...);
comparing two strings in SQL Server
There is no direct string compare function in SQL Server
CASE
WHEN str1 = str2 THEN 0
WHEN str1 < str2 THEN -1
WHEN str1 > str2 THEN 1
ELSE NULL --one of the strings is NULL so won't compare (added on edit)
END
Notes
- you can wraps this via a UDF using CREATE FUNCTION etc
- you may need NULL handling (in my code above, any NULL will report 1)
- str1 and str2 will be column names or @variables
How do I import modules or install extensions in PostgreSQL 9.1+?
Postgrseql 9.1 provides for a new command CREATE EXTENSION. You should use it to install modules.
Modules provided in 9.1 can be found here.. The include,
adminpack , auth_delay , auto_explain , btree_gin , btree_gist
, chkpass , citext , cube , dblink , dict_int
, dict_xsyn , dummy_seclabel , earthdistance , file_fdw , fuzzystrmatch
, hstore , intagg , intarray , isn , lo
, ltree , oid2name , pageinspect , passwordcheck , pg_archivecleanup
, pgbench , pg_buffercache , pgcrypto , pg_freespacemap , pgrowlocks
, pg_standby , pg_stat_statements , pgstattuple , pg_test_fsync , pg_trgm
, pg_upgrade , seg , sepgsql , spi , sslinfo , tablefunc
, test_parser , tsearch2 , unaccent , uuid-ossp , vacuumlo
, xml2
If for instance you wanted to install earthdistance, simply use this command:
CREATE EXTENSION earthdistance;
If you wanted to install an extension with a hyphen in its name, like uuid-ossp, you need to enclose the extension name in double quotes:
CREATE EXTENSION "uuid-ossp";
- Read more about contrib, and the modules available in 9.1.
- Read about the new extension infrastructure, and the SQL commands to manage it here You can now more easily uninstall a module, see
DROP EXTENSION. You can also get an extension list, and there is basic support for version numbers.
vi/vim editor, copy a block (not usual action)
just use V to select lines or v to select chars or Ctrlv to select a block.
When the selection spans the area you'd like to copy just hit y and use p to paste it anywhere you like...
Has an event handler already been added?
This example shows how to use the method GetInvocationList() to retrieve delegates to all the handlers that have been added. If you are looking to see if a specific handler (function) has been added then you can use array.
public class MyClass
{
event Action MyEvent;
}
...
MyClass myClass = new MyClass();
myClass.MyEvent += SomeFunction;
...
Action[] handlers = myClass.MyEvent.GetInvocationList(); //this will be an array of 1 in this example
Console.WriteLine(handlers[0].Method.Name);//prints the name of the method
You can examine various properties on the Method property of the delegate to see if a specific function has been added.
If you are looking to see if there is just one attached, you can just test for null.
Using MySQL with Entity Framework
Be careful using connector .net, Connector 6.6.5 have a bug, it is not working for inserting tinyint values as identity, for example:
create table person(
Id tinyint unsigned primary key auto_increment,
Name varchar(30)
);
if you try to insert an object like this:
Person p;
p = new Person();
p.Name = 'Oware'
context.Person.Add(p);
context.SaveChanges();
You will get a Null Reference Exception:
Referencia a objeto no establecida como instancia de un objeto.:
en MySql.Data.Entity.ListFragment.WriteSql(StringBuilder sql)
en MySql.Data.Entity.SelectStatement.WriteSql(StringBuilder sql)
en MySql.Data.Entity.InsertStatement.WriteSql(StringBuilder sql)
en MySql.Data.Entity.SqlFragment.ToString()
en MySql.Data.Entity.InsertGenerator.GenerateSQL(DbCommandTree tree)
en MySql.Data.MySqlClient.MySqlProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree)
en System.Data.Common.DbProviderServices.CreateCommandDefinition(DbCommandTree commandTree)
en System.Data.Common.DbProviderServices.CreateCommand(DbCommandTree commandTree)
en System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree)
en System.Data.Mapping.Update.Internal.DynamicUpdateCommand.CreateCommand(UpdateTranslator translator, Dictionary`2 identifierValues)
en System.Data.Mapping.Update.Internal.DynamicUpdateCommand.Execute(UpdateTranslator translator, EntityConnection connection, Dictionary`2 identifierValues, List`1 generatedValues)
en System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter)
en System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache)
en System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options)
en System.Data.Entity.Internal.InternalContext.SaveChanges()
en System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
en System.Data.Entity.DbContext.SaveChanges()
Until now I haven't found a solution, I had to change my tinyint identity to unsigned int identity, this solved the problem but this is not the right solution.
If you use an older version of Connector.net (I used 6.4.4) you won't have this problem.
If someone knows about the solution, please contact me.
Cheers!
Oware
Setting an int to Infinity in C++
int min and max values
Int -2,147,483,648 / 2,147,483,647 Int 64 -9,223,372,036,854,775,808 / 9,223,372,036,854,775,807
i guess you could set a to equal 9,223,372,036,854,775,807 but it would need to be an int64
if you always want a to be grater that b why do you need to check it? just set it to be true always
What's the best way to detect a 'touch screen' device using JavaScript?
Extent jQuery support object:
jQuery.support.touch = 'ontouchend' in document;
And now you can check it anywhere, like this:
if( jQuery.support.touch )
// do touch stuff
Simple VBA selection: Selecting 5 cells to the right of the active cell
This example selects a new Range of Cells defined by the current cell to a cell 5 to the right.
Note that .Offset takes arguments of Offset(row, columns) and can be quite useful.
Sub testForStackOverflow()
Range(ActiveCell, ActiveCell.Offset(0, 5)).Copy
End Sub
How do I add a newline to command output in PowerShell?
I think you had the correct idea with your last example. You only got an error because you were trying to put quotes inside an already quoted string. This will fix it:
gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { write-output ($_.GetValue("DisplayName") + "`n") }
Edit: Keith's $() operator actually creates a better syntax (I always forget about this one). You can also escape quotes inside quotes as so:
gci -path hklm:\software\microsoft\windows\currentversion\uninstall | ForEach-Object -Process { write-output "$($_.GetValue(`"DisplayName`"))`n" }
What is a postback?
So far I've seen the right answer alluded to repeatedly, and almost everyone has come shy of what I consider subjectively to be the mark.
Let's start with the basics:
An HTTP request can be any of the HTTP verbs, but the two that people use most are GET and POST. Well, those are the two a programmer uses most frequently. The others all have some purpose, if they're implemented on the server. When you send information to the server, you can do so either through the use of the URL (to request a page) or within the body of the request (POST, PUT, DELETE, for instance).
Now you'll remark (I'm sure) that the URL in a GET request often contains data, and this is true, but according to W3C, you should not use GET to alter state, and yet we do often. It's sort of a hack that we all agree is an actual use, and not a hack. Whether that makes it a hack or an actual implementation detail I leave up to you.
So when you send the body of the POST (skipping the others for now, you can figure it out from here) with the form elements, you're sending back certain elements. How those elements are defined is up to you and to the environment you're working in. You could post to a server with a JSON element in the body, or with XML, or with form fields. Generally we do posts from a FORM element in the body of the HTML.
Now everyone says, "oh, a postback is a subsequent request to a page." But, that's not true. A postback is when you send data via POST -> back to the server. I say this because the difference between a GET request and a POST request is if data is included in the body (and the verb used, but the client usually knows how to deal with that). You could postback to the page on the first time the page is visited, and in fact ASP.NET has tools for doing that in the library. You could certainly have a desktop client POST data to a server (think Twitter) without showing any webpage at all from the server (ok, so twitter is probably not the best concept to use for an example here, but I want to illustrate that you can use a client that doesn't show the webpage, so no request is necessary).
So really what you should read there in "postback" is "I'm POSTing data BACK to the server for processing". It's presumed that you retrieved the page initially with a GET to show the user the <form> element that has <input> fields for them to interact with, and that at the end you're sending data back. But I hope you can see that it doesn't have to be in that order.
So here's something else to consider:
What if you gave the user a page with a bunch of <input>s and no <form> but instead, had a button wired up in javascript to concat all those <input>s with &value-n= and send them as a GET? Does the same thing, but violates that concept of only using GET for requests. (possibly) ensuing discussion encourages me to reinforce that GET should have no side effects (no updating values)
It's how come you can send someone a link to a google search, for instance. So we don't ALWAYS have to POST BACK to the server to get data.
Hope this helps. Cheers
How to get an array of unique values from an array containing duplicates in JavaScript?
Edited
ES6 solution:
[...new Set(a)];
Alternative:
Array.from(new Set(a));
Old response. O(n^2) (do not use it with large arrays!)
var arrayUnique = function(a) {
return a.reduce(function(p, c) {
if (p.indexOf(c) < 0) p.push(c);
return p;
}, []);
};
Fastest way to check a string contain another substring in JavaScript?
In ES6, the includes() method is used to determine whether one string may be found within another string, returning true or false as appropriate.
var str = 'To be, or not to be, that is the question.';
console.log(str.includes('To be')); // true
console.log(str.includes('question')); // true
console.log(str.includes('nonexistent')); // false
Here is jsperf between
var ret = str.includes('one');
And
var ret = (str.indexOf('one') !== -1);
As the result shown in jsperf, it seems both of them perform well.
Launch an event when checking a checkbox in Angular2
Template: You can either use the native change event or NgModel directive's ngModelChange.
<input type="checkbox" (change)="onNativeChange($event)"/>
or
<input type="checkbox" ngModel (ngModelChange)="onNgModelChange($event)"/>
TS:
onNativeChange(e) { // here e is a native event
if(e.target.checked){
// do something here
}
}
onNgModelChange(e) { // here e is a boolean, true if checked, otherwise false
if(e){
// do something here
}
}
jQuery - determine if input element is textbox or select list
If you just want to check the type, you can use jQuery's .is() function,
Like in my case I used below,
if($("#id").is("select")) {
alert('Select');
else if($("#id").is("input")) {
alert("input");
}
The real difference between "int" and "unsigned int"
The problem is that you invoked Undefined Behaviour.
When you invoke UB anything can happen.
The assignments are ok; there is an implicit conversion in the first line
int x = 0xFFFFFFFF;
unsigned int y = 0xFFFFFFFF;
However, the call to printf, is not ok
printf("%d, %d, %u, %u", x, y, x, y);
It is UB to mismatch the % specifier and the type of the argument.
In your case you specify 2 ints and 2 unsigned ints in this order by provide 1 int, 1 unsigned int, 1 int, and 1 unsigned int.
Don't do UB!
How do I Sort a Multidimensional Array in PHP
You can use array_multisort()
Try something like this:
foreach ($mdarray as $key => $row) {
// replace 0 with the field's index/key
$dates[$key] = $row[0];
}
array_multisort($dates, SORT_DESC, $mdarray);
For PHP >= 5.5.0 just extract the column to sort by. No need for the loop:
array_multisort(array_column($mdarray, 0), SORT_DESC, $mdarray);
load iframe in bootstrap modal
I came across this implementation in Codepen. I hope you find it helpful.
this.on('hidden.bs.modal', function(){
$(this).find('iframe').html("").attr("src", "");
});
Removing carriage return and new-line from the end of a string in c#
For us VBers:
TrimEnd(New Char() {ControlChars.Cr, ControlChars.Lf})
Using braces with dynamic variable names in PHP
I was in a position where I had 6 identical arrays and I needed to pick the right one depending on another variable and then assign values to it. In the case shown here $comp_cat was 'a' so I needed to pick my 'a' array ( I also of course had 'b' to 'f' arrays)
Note that the values for the position of the variable in the array go after the closing brace.
${'comp_cat_'.$comp_cat.'_arr'}[1][0] = "FRED BLOGGS";
${'comp_cat_'.$comp_cat.'_arr'}[1][1] = $file_tidy;
echo 'First array value is '.$comp_cat_a_arr[1][0].' and the second value is .$comp_cat_a_arr[1][1];
Remove border from buttons
For removing the default 'blue-border' from button on button focus:
In Html:
<button class="new-button">New Button...</button>
And in Css
button.new-button:focus {
outline: none;
}
Hope it helps :)
Switching to landscape mode in Android Emulator
I'm using Android Studio and none of the suggestions worked. I can turn the emulator but it stays in portrait. I didn't want to add a command in the manifest forcing landscape. The fix for me was:
turn the emulator to landscape mode using ctrlF11 (the image will still be in portrait though)
Open up the camera in the os, it opens up in landscape mode, the only app that does this
without doing anything else, debug my app from Android Studio and now it shows up in landscape
Loading context in Spring using web.xml
You can also specify context location relatively to current classpath, which may be preferable
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:applicationContext*.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
SELECT INTO USING UNION QUERY
You can also try:
create table new_table as
select * from table1
union
select * from table2
How to remove multiple deleted files in Git repository
I had this issue of ghost files appearing in my repo after I deleted them and came across this neat command!
git add -A
It's essentially the same as git add -a and git add -u combined, but it's case sensitive. I got it from this awesome link (this link points to the version on archive.org now, because the original has converted to a spam/phishing page as of June 2016)
Reverse ip, find domain names on ip address
They're just trawling lists of web sites, and recording the resulting IP addresses in a database.
All you're seeing is the reverse mapping of that list. It's not guaranteed to be a full list (indeed more often than not it won't be) because it's impossible to learn every possible web site address.
PNG transparency issue in IE8
I use a CSS fix rather than JS to workaround my round cornered layer with transparent PNG inside
Try
.ie .whateverDivWrappingTheImage img {
background: #ffaabb; /* this should be the background color matching your design actually */
filter: chroma(#ffaabb); /* and this should match whatever value you put in background-color */
}
This may require more work on ie9 or later.
Can I give the col-md-1.5 in bootstrap?
As @bodi0 correctly said, it is not possible. You either have to extent Bootstrap's grid system (you can search and find various solutions, here is a 7-column example) or use nested rows e.g. http://bootply.com/dd50he9tGe.
In the case of nested rows you might not always get the exact result but a similar one
<div class="row">
<div class="col-lg-5">
<div class="row">
<div class="col-lg-4">1.67 (close to 1.5)</div>
<div class="col-lg-8">3.33 (close to 3.5)</div>
</div>
</div>
<div class="col-lg-7">
<div class="row">
<div class="col-lg-6">3.5</div>
<div class="col-lg-6">3.5</div>
</div>
</div>
</div>
Greater than less than, python
Check to make sure that both score and array[x] are numerical types. You might be comparing an integer to a string...which is heartbreakingly possible in Python 2.x.
>>> 2 < "2"
True
>>> 2 > "2"
False
>>> 2 == "2"
False
Edit
Further explanation: How does Python compare string and int?
How do I convert between big-endian and little-endian values in C++?
I have this code that allow me to convert from HOST_ENDIAN_ORDER (whatever it is) to LITTLE_ENDIAN_ORDER or BIG_ENDIAN_ORDER. I use a template, so if I try to convert from HOST_ENDIAN_ORDER to LITTLE_ENDIAN_ORDER and they happen to be the same for the machine for wich I compile, no code will be generated.
Here is the code with some comments:
// We define some constant for little, big and host endianess. Here I use
// BOOST_LITTLE_ENDIAN/BOOST_BIG_ENDIAN to check the host indianess. If you
// don't want to use boost you will have to modify this part a bit.
enum EEndian
{
LITTLE_ENDIAN_ORDER,
BIG_ENDIAN_ORDER,
#if defined(BOOST_LITTLE_ENDIAN)
HOST_ENDIAN_ORDER = LITTLE_ENDIAN_ORDER
#elif defined(BOOST_BIG_ENDIAN)
HOST_ENDIAN_ORDER = BIG_ENDIAN_ORDER
#else
#error "Impossible de determiner l'indianness du systeme cible."
#endif
};
// this function swap the bytes of values given it's size as a template
// parameter (could sizeof be used?).
template <class T, unsigned int size>
inline T SwapBytes(T value)
{
union
{
T value;
char bytes[size];
} in, out;
in.value = value;
for (unsigned int i = 0; i < size / 2; ++i)
{
out.bytes[i] = in.bytes[size - 1 - i];
out.bytes[size - 1 - i] = in.bytes[i];
}
return out.value;
}
// Here is the function you will use. Again there is two compile-time assertion
// that use the boost librarie. You could probably comment them out, but if you
// do be cautious not to use this function for anything else than integers
// types. This function need to be calles like this :
//
// int x = someValue;
// int i = EndianSwapBytes<HOST_ENDIAN_ORDER, BIG_ENDIAN_ORDER>(x);
//
template<EEndian from, EEndian to, class T>
inline T EndianSwapBytes(T value)
{
// A : La donnée à swapper à une taille de 2, 4 ou 8 octets
BOOST_STATIC_ASSERT(sizeof(T) == 2 || sizeof(T) == 4 || sizeof(T) == 8);
// A : La donnée à swapper est d'un type arithmetic
BOOST_STATIC_ASSERT(boost::is_arithmetic<T>::value);
// Si from et to sont du même type on ne swap pas.
if (from == to)
return value;
return SwapBytes<T, sizeof(T)>(value);
}
Type List vs type ArrayList in Java
(3) Collection myCollection = new ArrayList<?>();
I am using this typically. And only if I need List methods, I will use List. Same with ArrayList. You always can switch to more "narrow" interface, but you can't switch to more "wide".
Program does not contain a static 'Main' method suitable for an entry point
In my case (after renaming application namespace manually) I had to reselect the Startup object in Project properties.
How do I replace text in a selection?
This frustrated the heck out of me, and none of the above answers really got me what I wanted. I finally found the answer I was looking for, on a mac if you do ? + option + F it will bring up a Find-Replace bar at the bottom of your editor which is local to the file you have open.
There is an icon option which when hovered over says "In Selection" that you can select to find and replace within a selection. I've pointed to the correct icon in the screenshot below.
Hit replace all, and voila, all instances of '0' will be replaced with '255'.
Note: this feature is ONLY available when you use ? + option + F.
It does NOT appear when you use ? + shift + F.
Note: this will replace all instances of '0' with '255'. If you wanted to replace 0 (without the quotes) with 255, then just put 0 (without quotes) and 255 in the Find What: and Replace With: fields respectively.
Note:
option key is also labeled as the alt key.
? key is also labeled as the command key.
How to convert a string into double and vice versa?
I ended up using this handy macro:
#define STRING(value) [@(value) stringValue]
c++ bool question
Yes that is correct. "Boolean variables only have two possible values: true (1) and false (0)." cpp tutorial on boolean values
Difference between java.exe and javaw.exe
java.exe is the console app while javaw.exe is windows app (console-less). You can't have Console with javaw.exe.
Align an element to bottom with flexbox
I just found a solution for this.
for those who are not satisfied with the given answers can try this approach with flexbox
CSS
.myFlexContainer {
display: flex;
width: 100%;
}
.myFlexChild {
width: 100%;
display: flex;
/*
* set this property if this is set to column by other css class
* that is used by your target element
*/
flex-direction: row;
/*
* necessary for our goal
*/
flex-wrap: wrap;
height: 500px;
}
/* the element you want to put at the bottom */
.myTargetElement {
/*
* will not work unless flex-wrap is set to wrap and
* flex-direction is set to row
*/
align-self: flex-end;
}
HTML
<div class="myFlexContainer">
<div class="myFlexChild">
<p>this is just sample</p>
<a class="myTargetElement" href="#">set this to bottom</a>
</div>
</div>
Python: Get HTTP headers from urllib2.urlopen call?
Actually, it appears that urllib2 can do an HTTP HEAD request.
The question that @reto linked to, above, shows how to get urllib2 to do a HEAD request.
Here's my take on it:
import urllib2
# Derive from Request class and override get_method to allow a HEAD request.
class HeadRequest(urllib2.Request):
def get_method(self):
return "HEAD"
myurl = 'http://bit.ly/doFeT'
request = HeadRequest(myurl)
try:
response = urllib2.urlopen(request)
response_headers = response.info()
# This will just display all the dictionary key-value pairs. Replace this
# line with something useful.
response_headers.dict
except urllib2.HTTPError, e:
# Prints the HTTP Status code of the response but only if there was a
# problem.
print ("Error code: %s" % e.code)
If you check this with something like the Wireshark network protocol analazer, you can see that it is actually sending out a HEAD request, rather than a GET.
This is the HTTP request and response from the code above, as captured by Wireshark:
HEAD /doFeT HTTP/1.1
Accept-Encoding: identity
Host: bit.ly
Connection: close
User-Agent: Python-urllib/2.7HTTP/1.1 301 Moved
Server: nginx
Date: Sun, 19 Feb 2012 13:20:56 GMT
Content-Type: text/html; charset=utf-8
Cache-control: private; max-age=90
Location: http://www.kidsidebyside.org/?p=445
MIME-Version: 1.0
Content-Length: 127
Connection: close
Set-Cookie: _bit=4f40f738-00153-02ed0-421cf10a;domain=.bit.ly;expires=Fri Aug 17 13:20:56 2012;path=/; HttpOnly
However, as mentioned in one of the comments in the other question, if the URL in question includes a redirect then urllib2 will do a GET request to the destination, not a HEAD. This could be a major shortcoming, if you really wanted to only make HEAD requests.
The request above involves a redirect. Here is request to the destination, as captured by Wireshark:
GET /2009/05/come-and-draw-the-circle-of-unity-with-us/ HTTP/1.1
Accept-Encoding: identity
Host: www.kidsidebyside.org
Connection: close
User-Agent: Python-urllib/2.7
An alternative to using urllib2 is to use Joe Gregorio's httplib2 library:
import httplib2
url = "http://bit.ly/doFeT"
http_interface = httplib2.Http()
try:
response, content = http_interface.request(url, method="HEAD")
print ("Response status: %d - %s" % (response.status, response.reason))
# This will just display all the dictionary key-value pairs. Replace this
# line with something useful.
response.__dict__
except httplib2.ServerNotFoundError, e:
print (e.message)
This has the advantage of using HEAD requests for both the initial HTTP request and the redirected request to the destination URL.
Here's the first request:
HEAD /doFeT HTTP/1.1
Host: bit.ly
accept-encoding: gzip, deflate
user-agent: Python-httplib2/0.7.2 (gzip)
Here's the second request, to the destination:
HEAD /2009/05/come-and-draw-the-circle-of-unity-with-us/ HTTP/1.1
Host: www.kidsidebyside.org
accept-encoding: gzip, deflate
user-agent: Python-httplib2/0.7.2 (gzip)
How can I stop "property does not exist on type JQuery" syntax errors when using Typescript?
I think this is the most readable solution:
($("div.printArea") as any).printArea();
Java Look and Feel (L&F)
There is a lot of possibilities for LaFs :
- The native for your system
- The nimbus LaF
- Web LaF
- The substance project (forked into the Insubstantial project)
- Napkin LaF
- Synthetica
- Quaqua (looks like aqua from MacOS X)
- Seaglass
- JGoodies
- Liquidlnf
- The Alloy Look and Feel
- PgsLookAndFeel
- JTatoo
- Jide look and feel
- etc.
Resources :
- Best Java Swing Look and Feel Themes | Top 10 (A lot of the preview images on this page are now missing)
- oracle.com - Modifying the Look and Feel
- wikipedia.org - Pluggable look and feel
- Java2s.com - Look and feel
Related topics :
Change background position with jQuery
Here you go:
$(document).ready(function(){
$('#submenu li').hover(function(){
$('#carousel').css('background-position', '10px 10px');
}, function(){
$('#carousel').css('background-position', '');
});
});
Login to Microsoft SQL Server Error: 18456
In my case multiple wrong attempts locked the account.To do that I had tried running the below query and it worked: ALTER LOGIN WITH PASSWORD= UNLOCK And make sure to set the option "Enforce Password Security" option for specific user to be unchecked by right click on Sql Server -> Properties.
When to use extern in C++
This is useful when you want to have a global variable. You define the global variables in some source file, and declare them extern in a header file so that any file that includes that header file will then see the same global variable.
Format bytes to kilobytes, megabytes, gigabytes
It's a little late but a slightly faster version of the accepted answer is below:
function formatBytes($bytes, $precision)
{
$unit_list = array
(
'B',
'KB',
'MB',
'GB',
'TB',
);
$bytes = max($bytes, 0);
$index = floor(log($bytes, 2) / 10);
$index = min($index, count($unit_list) - 1);
$bytes /= pow(1024, $index);
return round($bytes, $precision) . ' ' . $unit_list[$index];
}
It's more efficient, due to performing a single log-2 operation instead of two log-e operations.
It's actually faster to do the more obvious solution below, however:
function formatBytes($bytes, $precision)
{
$unit_list = array
(
'B',
'KB',
'MB',
'GB',
'TB',
);
$index_max = count($unit_list) - 1;
$bytes = max($bytes, 0);
for ($index = 0; $bytes >= 1024 && $index < $index_max; $index++)
{
$bytes /= 1024;
}
return round($bytes, $precision) . ' ' . $unit_list[$index];
}
This is because as the index is calculated at the same time as the value of the number of bytes in the appropriate unit. This cut the execution time by about 35% (a 55% speed increase).
How to get the path of a running JAR file?
the selected answer above is not working if you run your jar by click on it from Gnome desktop environment (not from any script or terminal).
Instead, I have fond that the following solution is working everywhere:
try {
return URLDecoder.decode(ClassLoader.getSystemClassLoader().getResource(".").getPath(), "UTF-8");
} catch (UnsupportedEncodingException e) {
return "";
}
What's the best visual merge tool for Git?
Meld is a free, open-source, and cross-platform (UNIX/Linux, OSX, Windows) diff/merge tool.
Here's how to install it on:
- Ubuntu
- Mac
- Windows: "The recommended version of Meld for Windows is the most recent release, available as an MSI from https://meldmerge.org"
How can I remove all text after a character in bash?
Let's say you have a path with a file in this format:
/dirA/dirB/dirC/filename.file
Now you only want the path which includes four "/". Type
$ echo "/dirA/dirB/dirC/filename.file" | cut -f1-4 -d"/"
and your output will be
/dirA/dirB/dirC
The advantage of using cut is that you can also cut out the uppest directory as well as the file (in this example), so if you type
$ echo "/dirA/dirB/dirC/filename.file" | cut -f1-3 -d"/"
your output would be
/dirA/dirB
Though you can do the same from the other side of the string, it would not make that much sense in this case as typing
$ echo "/dirA/dirB/dirC/filename.file" | cut -f2-4 -d"/"
results in
dirA/dirB/dirC
In some other cases the last case might also be helpful. Mind that there is no "/" at the beginning of the last output.
Generating random strings with T-SQL
I use this procedure that I developed simply stipluate the charaters you want to be able to display in the input variables, you can define the length too. Hope this formats well, I am new to stack overflow.
IF EXISTS (SELECT * FROM sys.objects WHERE type = 'P' AND object_id = OBJECT_ID(N'GenerateARandomString'))
DROP PROCEDURE GenerateARandomString
GO
CREATE PROCEDURE GenerateARandomString
(
@DESIREDLENGTH INTEGER = 100,
@NUMBERS VARCHAR(50)
= '0123456789',
@ALPHABET VARCHAR(100)
='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz',
@SPECIALS VARCHAR(50)
= '_=+-$£%^&*()"!@~#:',
@RANDOMSTRING VARCHAR(8000) OUT
)
AS
BEGIN
-- Author David Riley
-- Version 1.0
-- You could alter to one big string .e.e numebrs , alpha special etc
-- added for more felxibility in case I want to extend i.e put logic in for 3 numbers, 2 pecials 3 numbers etc
-- for now just randomly pick one of them
DECLARE @SWAP VARCHAR(8000); -- Will be used as a tempoary buffer
DECLARE @SELECTOR INTEGER = 0;
DECLARE @CURRENTLENGHT INTEGER = 0;
WHILE @CURRENTLENGHT < @DESIREDLENGTH
BEGIN
-- Do we want a number, special character or Alphabet Randonly decide?
SET @SELECTOR = CAST(ABS(CHECKSUM(NEWID())) % 3 AS INTEGER); -- Always three 1 number , 2 alphaBET , 3 special;
IF @SELECTOR = 0
BEGIN
SET @SELECTOR = 3
END;
-- SET SWAP VARIABLE AS DESIRED
SELECT @SWAP = CASE WHEN @SELECTOR = 1 THEN @NUMBERS WHEN @SELECTOR = 2 THEN @ALPHABET ELSE @SPECIALS END;
-- MAKE THE SELECTION
SET @SELECTOR = CAST(ABS(CHECKSUM(NEWID())) % LEN(@SWAP) AS INTEGER);
IF @SELECTOR = 0
BEGIN
SET @SELECTOR = LEN(@SWAP)
END;
SET @RANDOMSTRING = ISNULL(@RANDOMSTRING,'') + SUBSTRING(@SWAP,@SELECTOR,1);
SET @CURRENTLENGHT = LEN(@RANDOMSTRING);
END;
END;
GO
DECLARE @RANDOMSTRING VARCHAR(8000)
EXEC GenerateARandomString @RANDOMSTRING = @RANDOMSTRING OUT
SELECT @RANDOMSTRING
ImportError: No module named model_selection
Your sklearn version is too low, model_selection is imported by 0.18.1, so please update the sklearn version.
JQuery find first parent element with specific class prefix
Jquery later allowed you to to find the parents with the .parents() method.
Hence I recommend using:
var $div = $('#divid').parents('div[class^="div-a"]');
This gives all parent nodes matching the selector. To get the first parent matching the selector use:
var $div = $('#divid').parents('div[class^="div-a"]').eq(0);
For other such DOM traversal queries, check out the documentation on traversing the DOM.
How do you install Google frameworks (Play, Accounts, etc.) on a Genymotion virtual device?
Sometimes "ARM Translation Installer v1.1" is not working.. Here is the simple solution to install Google Play.
Go to this link: http://www.mediafire.com/download/jdn83v1v3bregyu/Galaxy+S4++HTC+One++Xperia+Z+-+4.2.2+-+with+Google+Apps+-+API+17+-+1080x1920.zip
Download the file from the link and extract to get the Android virtual device with Google Play store. The file will be in the name as “Galaxy S4 HTC One Xperia Z – 4.2.2 – with Google Apps – API 17 – 1080×1920".
Close all your Genymotion store running in the background.
Copy that extracted file in to the following folder. C:\Users\'username'\AppData\Local\Genymobile\Genymotion\deployed
After you copy you should see this path: C:\Users\'username'\AppData\Local\Genymobile\Genymotion\deployed\Galaxy S4 HTC One Xperia Z - 4.2.2 - with Google Apps - API 17 - 1080x1920
Inside the “Galaxy S4 HTC One Xperia Z – 4.2.2 – with Google Apps – API 17 – 1080×1920" folder you will see many *.vmdk and *.vbox files.
Now open VirtualBox and select Machine->Add and browse for the above folder and import the *.vbox file.
Restart Genymotion. Done.
Ignore mapping one property with Automapper
From Jimmy Bogard: CreateMap<Foo, Bar>().ForMember(x => x.Blarg, opt => opt.Ignore());
It's in one of the comments at his blog.
How to get the list of all installed color schemes in Vim?
Here is a small function I wrote to try all the colorschemes in $VIMRUNTIME/colors directory.
Add the below function to your vimrc, then open your source file and call the function from command.
function! DisplayColorSchemes()
let currDir = getcwd()
exec "cd $VIMRUNTIME/colors"
for myCol in split(glob("*"), '\n')
if myCol =~ '\.vim'
let mycol = substitute(myCol, '\.vim', '', '')
exec "colorscheme " . mycol
exec "redraw!"
echo "colorscheme = ". myCol
sleep 2
endif
endfor
exec "cd " . currDir
endfunction
How do I append a node to an existing XML file in java
The following complete example will read an existing server.xml file from the current directory, append a new Server and re-write the file to server.xml. It does not work without an existing .xml file, so you will need to modify the code to handle that case.
import java.util.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
import javax.xml.transform.dom.*;
import org.w3c.dom.*;
import javax.xml.parsers.*;
public class AddXmlNode {
public static void main(String[] args) throws Exception {
DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
Document document = documentBuilder.parse("server.xml");
Element root = document.getDocumentElement();
Collection<Server> servers = new ArrayList<Server>();
servers.add(new Server());
for (Server server : servers) {
// server elements
Element newServer = document.createElement("server");
Element name = document.createElement("name");
name.appendChild(document.createTextNode(server.getName()));
newServer.appendChild(name);
Element port = document.createElement("port");
port.appendChild(document.createTextNode(Integer.toString(server.getPort())));
newServer.appendChild(port);
root.appendChild(newServer);
}
DOMSource source = new DOMSource(document);
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
StreamResult result = new StreamResult("server.xml");
transformer.transform(source, result);
}
public static class Server {
public String getName() { return "foo"; }
public Integer getPort() { return 12345; }
}
}
Example server.xml file:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Servers>
<server>
<name>something</name>
<port>port</port>
</server>
</Servers>
The main change to your code is not creating a new "root" element. The above example just uses the current root node from the existing server.xml and then just appends a new Server element and re-writes the file.
Java multiline string
String.join
Java 8 added a new static method to java.lang.String which offers a slightly better alternative:
String.join(
CharSequence delimiter ,
CharSequence... elements
)
Using it:
String s = String.join(
System.getProperty("line.separator"),
"First line.",
"Second line.",
"The rest.",
"And the last!"
);
Restarting cron after changing crontab file?
Try this out: sudo cron reload
It works for me on ubuntu 12.10
How to group by month from Date field using sql
DATEPART function doesn't work on MySQL 5.6, instead use MONTH('2018-01-01')
How to form a correct MySQL connection string?
Here is an example:
MySqlConnection con = new MySqlConnection(
"Server=ServerName;Database=DataBaseName;UID=username;Password=password");
MySqlCommand cmd = new MySqlCommand(
" INSERT Into Test (lat, long) VALUES ('"+OSGconv.deciLat+"','"+
OSGconv.deciLon+"')", con);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
Format a datetime into a string with milliseconds
from datetime import datetime
from time import clock
t = datetime.utcnow()
print 't == %s %s\n\n' % (t,type(t))
n = 100000
te = clock()
for i in xrange(1):
t_stripped = t.strftime('%Y%m%d%H%M%S%f')
print clock()-te
print t_stripped," t.strftime('%Y%m%d%H%M%S%f')"
print
te = clock()
for i in xrange(1):
t_stripped = str(t).replace('-','').replace(':','').replace('.','').replace(' ','')
print clock()-te
print t_stripped," str(t).replace('-','').replace(':','').replace('.','').replace(' ','')"
print
te = clock()
for i in xrange(n):
t_stripped = str(t).translate(None,' -:.')
print clock()-te
print t_stripped," str(t).translate(None,' -:.')"
print
te = clock()
for i in xrange(n):
s = str(t)
t_stripped = s[:4] + s[5:7] + s[8:10] + s[11:13] + s[14:16] + s[17:19] + s[20:]
print clock()-te
print t_stripped," s[:4] + s[5:7] + s[8:10] + s[11:13] + s[14:16] + s[17:19] + s[20:] "
result
t == 2011-09-28 21:31:45.562000 <type 'datetime.datetime'>
3.33410112179
20110928212155046000 t.strftime('%Y%m%d%H%M%S%f')
1.17067364707
20110928212130453000 str(t).replace('-','').replace(':','').replace('.','').replace(' ','')
0.658806915404
20110928212130453000 str(t).translate(None,' -:.')
0.645189262881
20110928212130453000 s[:4] + s[5:7] + s[8:10] + s[11:13] + s[14:16] + s[17:19] + s[20:]
Use of translate() and slicing method run in same time
translate() presents the advantage to be usable in one line
Comparing the times on the basis of the first one:
1.000 * t.strftime('%Y%m%d%H%M%S%f')
0.351 * str(t).replace('-','').replace(':','').replace('.','').replace(' ','')
0.198 * str(t).translate(None,' -:.')
0.194 * s[:4] + s[5:7] + s[8:10] + s[11:13] + s[14:16] + s[17:19] + s[20:]
"Invalid form control" only in Google Chrome
I had the error:
An invalid form control with name='telefono' is not focusable.
This was happening because I was not using the required field correctly, which enabled and disabled when clicking on a checkbok. The solution was to remove the required attribute whenever the checkbok was not marked and mark it as required when the checkbox was marked.
var telefono = document.getElementById("telefono");
telefono.removeAttribute("required");
Changing the interval of SetInterval while it's running
Simple answer is you can't update an interval of already created timer. (There is only two functions setInterval/setTimer and clearInterval/clearTimer, so having a timerId you can only deactivate it.) But you can made some workarounds. Take a look at this github repo.
Select tableview row programmatically
Calling this method does not cause the delegate to receive a
tableView:willSelectRowAtIndexPath:ortableView:didSelectRowAtIndexPath:message, nor does it sendUITableViewSelectionDidChangeNotificationnotifications to observers.
What I would do is:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[self doSomethingWithRowAtIndexPath:indexPath];
}
And then, from where you wanted to call selectRowAtIndexPath, you instead call doSomethingWithRowAtIndexPath. On top of that, you can additionally also call selectRowAtIndexPath if you want the UI feedback to happen.
Add data to JSONObject
The answer is to use a JSONArray as well, and to dive "deep" into the tree structure:
JSONArray arr = new JSONArray();
arr.put (...); // a new JSONObject()
arr.put (...); // a new JSONObject()
JSONObject json = new JSONObject();
json.put ("aoColumnDefs",arr);
How to iterate (keys, values) in JavaScript?
Try this:
var value;
for (var key in dictionary) {
value = dictionary[key];
// your code here...
}
Foreach in a Foreach in MVC View
You have:
foreach (var category in Model.Categories)
and then
@foreach (var product in Model)
Based on that view and model it seems that Model is of type Product if yes then the second foreach is not valid. Actually the first one could be the one that is invalid if you return a collection of Product.
UPDATE:
You are right, I am returning the model of type Product. Also, I do understand what is wrong now that you've pointed it out. How am I supposed to do what I'm trying to do then if I can't do it this way?
I'm surprised your code compiles when you said you are returning a model of Product type. Here's how you can do it:
@foreach (var category in Model)
{
<h3><u>@category.Name</u></h3>
<div>
<ul>
@foreach (var product in category.Products)
{
<li>
put the rest of your code
</li>
}
</ul>
</div>
}
That suggest that instead of returning a Product, you return a collection of Category with Products. Something like this in EF:
// I am typing it here directly
// so I'm not sure if this is the correct syntax.
// I assume you know how to do this,
// anyway this should give you an idea.
context.Categories.Include(o=>o.Product)
Compiler error "archive for required library could not be read" - Spring Tool Suite
I was using Eclipse as IDE and I was getting very same error. I had to do Project->Maven->Update Project. Select all the checkboxes below except "offline" esp. the one "Force update of snapshots/releases" and click OK. Did the Clean Build for the Project again.
Convert string to boolean in C#
I know this is not an ideal question to answer but as the OP seems to be a beginner, I'd love to share some basic knowledge with him... Hope everybody understands
OP, you can convert a string to type Boolean by using any of the methods stated below:
string sample = "True";
bool myBool = bool.Parse(sample);
///or
bool myBool = Convert.ToBoolean(sample);
bool.Parse expects one parameter which in this case is sample, .ToBoolean also expects one parameter.
You can use TryParse which is the same as Parse but it doesn't throw any exception :)
string sample = "false";
Boolean myBool;
if (Boolean.TryParse(sample , out myBool))
{
}
Please note that you cannot convert any type of string to type Boolean because the value of a Boolean can only be True or False
Hope you understand :)
What's the difference between next() and nextLine() methods from Scanner class?
From javadocs
next() Returns the next token if it matches the pattern constructed from the specified string. nextLine() Advances this scanner past the current line and returns the input that was skipped.
Which one you choose depends which suits your needs best. If it were me reading a whole file I would go for nextLine until I had all the file.
Array functions in jQuery
You can use Underscore.js. It really makes things simple.
For example, removing elements from an array, you need to do:
_.without([1, 2, 3], 2);
And the result will be [1, 3].
It reduces the code that you write using jQuery.grep, etc. in jQuery.
Java String declaration
There is a small difference between both.
Second declaration assignates the reference associated to the constant SOMEto the variable str
First declaration creates a new String having for value the value of the constant SOME and assignates its reference to the variable str.
In the first case, a second String has been created having the same value that SOME which implies more inititialization time. As a consequence, you should avoid it. Furthermore, at compile time, all constants SOMEare transformed into the same instance, which uses far less memory.
As a consequence, always prefer second syntax.
How to restart Jenkins manually?
If you want to just reload the configuration file, one can do
<jenkins_url>/reload
This is quicker if you have made some small change in the configuration file, like config.xml directly in the file system or made copies of the job through the filesystem (not through the browser).
RegEx for valid international mobile phone number
After stripping all characters except '+' and digits from your input, this should do it:
^\+[1-9]{1}[0-9]{3,14}$
If you want to be more exact with the country codes see this question on List of phone number country codes
However, I would try to be not too strict with my validation. Users get very frustrated if they are told their valid numbers are not acceptable.
Check if number is decimal
If you are working with form validation. Then in this case form send string. I used following code to check either form input is a decimal number or not. I hope this will work for you too.
function is_decimal($input = '') {
$alphabets = str_split($input);
$find = array('0','1','2','3','4','5','6','7','8','9','.'); // Please note: All intiger numbers are decimal. If you want to check numbers without point "." then you can remove '.' from array.
foreach ($alphabets as $key => $alphabet) {
if (!in_array($alphabet, $find)) {
return false;
}
}
// Check if user has enter "." point more then once.
if (substr_count($input, ".") > 1) {
return false;
}
return true;
}
What's with the dollar sign ($"string")
is a concept that languages like Perl have had for quite a while, and now we’ll get this ability in C# as well. In String Interpolation, we simply prefix the string with a $ (much like we use the @ for verbatim strings). Then, we simply surround the expressions we want to interpolate with curly braces (i.e. { and }):
It looks a lot like the String.Format() placeholders, but instead of an index, it is the expression itself inside the curly braces. In fact, it shouldn’t be a surprise that it looks like String.Format() because that’s really all it is – syntactical sugar that the compiler treats like String.Format() behind the scenes.
A great part is, the compiler now maintains the placeholders for you so you don’t have to worry about indexing the right argument because you simply place it right there in the string.
C# string interpolation is a method of concatenating,formatting and manipulating strings. This feature was introduced in C# 6.0. Using string interpolation, we can use objects and expressions as a part of the string interpolation operation.
Syntax of string interpolation starts with a ‘$’ symbol and expressions are defined within a bracket {} using the following syntax.
{<interpolatedExpression>[,<alignment>][:<formatString>]}
Where:
- interpolatedExpression - The expression that produces a result to be formatted
- alignment - The constant expression whose value defines the minimum number of characters in the string representation of the result of the interpolated expression. If positive, the string representation is right-aligned; if negative, it's left-aligned.
- formatString - A format string that is supported by the type of the expression result.
The following code example concatenates a string where an object, author as a part of the string interpolation.
string author = "Mohit";
string hello = $"Hello {author} !";
Console.WriteLine(hello); // Hello Mohit !
Read more on C#/.NET Little Wonders: String Interpolation in C# 6
Read SQL Table into C# DataTable
var table = new DataTable();
using (var da = new SqlDataAdapter("SELECT * FROM mytable", "connection string"))
{
da.Fill(table);
}
How to change root logging level programmatically for logback
I seem to be having success doing
org.jboss.logmanager.Logger logger = org.jboss.logmanager.Logger.getLogger("");
logger.setLevel(java.util.logging.Level.ALL);
Then to get detailed logging from netty, the following has done it
org.slf4j.impl.SimpleLogger.setLevel(org.slf4j.impl.SimpleLogger.TRACE);
How to set the first option on a select box using jQuery?
Here is the best solution im using. This will apply for over 1 slectbox
$("select").change(function(){_x000D_
var thisval = $(this).val();_x000D_
$("select").prop('selectedIndex',0);_x000D_
$(this).val(thisval);_x000D_
})How to decide when to use Node.js?
I can share few points where&why to use node js.
- For realtime applications like chat,collaborative editing better we go with nodejs as it is event base where fire event and data to clients from server.
- Simple and easy to understand as it is javascript base where most of people have idea.
- Most of current web applications going towards angular js&backbone, with node it is easy to interact with client side code as both will use json data.
- Lot of plugins available.
Drawbacks:-
- Node will support most of databases but best is mongodb which won't support complex joins and others.
- Compilation Errors...developer should handle each and every exceptions other wise if any error accord application will stop working where again we need to go and start it manually or using any automation tool.
Conclusion:- Nodejs best to use for simple and real time applications..if you have very big business logic and complex functionality better should not use nodejs. If you want to build an application along with chat and any collaborative functionality.. node can be used in specific parts and remain should go with your convenience technology.
Parsing JSON array with PHP foreach
You need to tell it which index in data to use, or double loop through all.
E.g., to get the values in the 4th index in the outside array.:
foreach($user->data[3]->values as $values)
{
echo $values->value . "\n";
}
To go through all:
foreach($user->data as $mydata)
{
foreach($mydata->values as $values) {
echo $values->value . "\n";
}
}
Python OpenCV2 (cv2) wrapper to get image size?
import cv2
img=cv2.imread('my_test.jpg')
img_info = img.shape
print("Image height :",img_info[0])
print("Image Width :", img_info[1])
print("Image channels :", img_info[2])
Ouput :-
My_test.jpg link ---> https://i.pinimg.com/originals/8b/ca/f5/8bcaf5e60433070b3210431e9d2a9cd9.jpg
Append a dictionary to a dictionary
dict.update() looks like it will do what you want...
>> orig.update(extra)
>>> orig
{'A': 1, 'C': 3, 'B': 2, 'E': 5, 'D': 4}
>>>
Perhaps, though, you don't want to update your original dictionary, but work on a copy:
>>> dest = orig.copy()
>>> dest.update(extra)
>>> orig
{'A': 1, 'C': 3, 'B': 2}
>>> dest
{'A': 1, 'C': 3, 'B': 2, 'E': 5, 'D': 4}
How do I analyze a program's core dump file with GDB when it has command-line parameters?
It doesn't matter if the executable has arguments or not. To run GDB on any binary with a generated core file, the syntax is below.
Syntax:
gdb <binary name> <generated core file>
Eg:
gdb l3_entity 6290-corefile
Let me take the below example for more understanding.
bash-4.1$ **gdb l3_entity 6290-corefile**
**Core was generated** by `/dir1/dir2/dir3/l3_entity **Program terminated with signal SIGABRT, Aborted.**
#0
#1
#2
#3
#4
#5
#6
#7
#8
#9
#10
(gdb)
From the above output, you can guess something about core, whether it is a NULL access, SIGABORT, etc..
These numbers #0 to #10 are the stack frames of GDB. These stack frames are not of your binary. In the above 0 - 10 frames if you suspect anything wrong select that frame
(gdb) frame 8
Now to see more details about it:
(gdb) list +
To investigate the issue further, you can print the suspected variable values here at this point in time.
(gdb) print thread_name
Add values to app.config and retrieve them
sorry for late answer but may be my code may help u.
I placed 3 buttons on the winform surface. button1 & 2 will set different value and button3 will retrieve current value. so when run my code first add the reference System.configuration
and click on first button and then click on 3rd button to see what value has been set. next time again click on second & 3rd button to see again what value has been set after change.
so here is the code.
using System.Configuration;
private void button1_Click(object sender, EventArgs e)
{
Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
config.AppSettings.Settings.Remove("DBServerName");
config.AppSettings.Settings.Add("DBServerName", "FirstAddedValue1");
config.Save(ConfigurationSaveMode.Modified);
}
private void button2_Click(object sender, EventArgs e)
{
Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
config.AppSettings.Settings.Remove("DBServerName");
config.AppSettings.Settings.Add("DBServerName", "SecondAddedValue1");
config.Save(ConfigurationSaveMode.Modified);
}
private void button3_Click(object sender, EventArgs e)
{
Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
MessageBox.Show(config.AppSettings.Settings["DBServerName"].Value);
}
How to limit depth for recursive file list?
Checkout the -maxdepth flag of find
find . -maxdepth 1 -type d -exec ls -ld "{}" \;
Here I used 1 as max level depth, -type d means find only directories, which then ls -ld lists contents of, in long format.
Entity Framework Provider type could not be loaded?
I sorted it out with [DeploymentItem] on my assembly initializing class
namespace MyTests
{
/// <summary>
/// Summary description for AssemblyTestInit
/// </summary>
[TestClass]
[DeploymentItem("EntityFramework.SqlServer.dll")]
public class AssemblyTestInit
{
public AssemblyTestInit()
{
}
private TestContext testContextInstance;
public TestContext TestContext
{
get
{
return testContextInstance;
}
set
{
testContextInstance = value;
}
}
[AssemblyInitialize()]
public static void DbContextInitialize(TestContext testContext)
{
Database.SetInitializer<TestContext>(new TestContextInitializer());
}
}
}
Find running median from a stream of integers
The most efficient way to calculate a percentile of a stream that I have found is the P² algorithm: Raj Jain, Imrich Chlamtac: The P² Algorithm for Dynamic Calculation of Quantiiles and Histograms Without Storing Observations. Commun. ACM 28(10): 1076-1085 (1985)
The algorithm is straight forward to implement and works extremely well. It is an estimate, however, so keep that in mind. From the abstract:
A heuristic algorithm is proposed for dynamic calculation qf the median and other quantiles. The estimates are produced dynamically as the observations are generated. The observations are not stored; therefore, the algorithm has a very small and fixed storage requirement regardless of the number of observations. This makes it ideal for implementing in a quantile chip that can be used in industrial controllers and recorders. The algorithm is further extended to histogram plotting. The accuracy of the algorithm is analyzed.
How do I access an access array item by index in handlebars?
Please try this, if you want to fetch first/last.
{{#each list}}
{{#if @first}}
<div class="active">
{{else}}
<div>
{{/if}}
{{/each}}
{{#each list}}
{{#if @last}}
<div class="last-element">
{{else}}
<div>
{{/if}}
{{/each}}
When should I use double or single quotes in JavaScript?
There is strictly no difference, so it is mostly a matter of taste and of what is in the string (or if the JavaScript code itself is in a string), to keep number of escapes low.
The speed difference legend might come from PHP world, where the two quotes have different behavior.
Inline Form nested within Horizontal Form in Bootstrap 3
I had problems aligning the label to the input(s) elements so I transferred the label element inside the form-inline and form-group too...and it works..
<div class="form-group">
<div class="col-xs-10">
<div class="form-inline">
<div class="form-group">
<label for="birthday" class="col-xs-2 control-label">Birthday:</label>
</div>
<div class="form-group">
<input type="text" class="form-control" placeholder="year"/>
</div>
<div class="form-group">
<input type="text" class="form-control" placeholder="month"/>
</div>
<div class="form-group">
<input type="text" class="form-control" placeholder="day"/>
</div>
</div>
</div>
</div>
Convert js Array() to JSon object for use with JQuery .ajax
You can iterate the key/value pairs of the saveData object to build an array of the pairs, then use join("&") on the resulting array:
var a = [];
for (key in saveData) {
a.push(key+"="+saveData[key]);
}
var serialized = a.join("&") // a=2&c=1
set up device for development (???????????? no permissions)
I had the same problem and I followed these steps:
# Clone this repository
git clone https://github.com/M0Rf30/android-udev-rules.git
cd android-udev-rules
# Copy rules file
sudo cp -v 51-android.rules /etc/udev/rules.d/51-android.rules
# OR create a sym-link to the rules file - choose this option if you'd like to update your udev rules using git.
sudo ln -sf "$PWD"/51-android.rules /etc/udev/rules.d/51-android.rules
# Change file permissions
sudo chmod a+r /etc/udev/rules.d/51-android.rules
# If adbusers group already exists remove old adbusers group
groupdel adbusers
# add the adbusers group if it's doesn't already exist
sudo mkdir -p /usr/lib/sysusers.d/ && sudo cp android-udev.conf /usr/lib/sysusers.d/
sudo systemd-sysusers # (1)
# OR on Fedora:
groupadd adbusers
# Add your user to the adbusers group
sudo usermod -a -G adbusers $(whoami)
# Restart UDEV
sudo udevadm control --reload-rules
sudo service udev restart
# OR on Fedora:
sudo systemctl restart systemd-udevd.service
# Restart the ADB server
adb kill-server
# Replug your Android device and verify that USB debugging is enabled in developer options
adb devices
# You should now see your device
The above steps are described on android-udev-rules. It worked for me.
Just be sure to confirm the dialog that will appear on your phone screen after replug it.
Reading JSON from a file?
Here is a copy of code which works fine for me
import json
with open("test.json") as json_file:
json_data = json.load(json_file)
print(json_data)
with the data
{
"a": [1,3,"asdf",true],
"b": {
"Hello": "world"
}
}
you may want to wrap your json.load line with a try catch because invalid JSON will cause a stacktrace error message.
wait process until all subprocess finish?
A Popen object has a .wait() method exactly defined for this: to wait for the completion of a given subprocess (and, besides, for retuning its exit status).
If you use this method, you'll prevent that the process zombies are lying around for too long.
(Alternatively, you can use subprocess.call() or subprocess.check_call() for calling and waiting. If you don't need IO with the process, that might be enough. But probably this is not an option, because your if the two subprocesses seem to be supposed to run in parallel, which they won't with (check_)call().)
If you have several subprocesses to wait for, you can do
exit_codes = [p.wait() for p in p1, p2]
which returns as soon as all subprocesses have finished. You then have a list of return codes which you maybe can evaluate.
jQuery SVG vs. Raphael
I prefer using RaphaelJS because it has great cross-browser abilities. However, some SVG & VML effects can't be achieved with RaphaelJS (complex gradients...).
Google has also developped a library of its own to enable SVG support in IE: http://svgweb.googlecode.com/files/svgweb-2009-08-20-B.zip
how to set auto increment column with sql developer
@tom-studee you were right, it's possible to do it in the data modeler.
Double click your table, then go to the column section. Here double click on the column which will have the auto increment. In the general section there is a checkbox "autoincrement", just tick it.
After that you can also go to the "autoincrement" section to customize it.
When you save it and ask the data modeler to generate the SQL script, you will see the sequence and trigger which represent your autoincrement.
Plotting a 2D heatmap with Matplotlib
I would use matplotlib's pcolor/pcolormesh function since it allows nonuniform spacing of the data.
Example taken from matplotlib:
import matplotlib.pyplot as plt
import numpy as np
# generate 2 2d grids for the x & y bounds
y, x = np.meshgrid(np.linspace(-3, 3, 100), np.linspace(-3, 3, 100))
z = (1 - x / 2. + x ** 5 + y ** 3) * np.exp(-x ** 2 - y ** 2)
# x and y are bounds, so z should be the value *inside* those bounds.
# Therefore, remove the last value from the z array.
z = z[:-1, :-1]
z_min, z_max = -np.abs(z).max(), np.abs(z).max()
fig, ax = plt.subplots()
c = ax.pcolormesh(x, y, z, cmap='RdBu', vmin=z_min, vmax=z_max)
ax.set_title('pcolormesh')
# set the limits of the plot to the limits of the data
ax.axis([x.min(), x.max(), y.min(), y.max()])
fig.colorbar(c, ax=ax)
plt.show()
Expression must be a modifiable lvalue
In C, you will also experience the same error if you declare a:
char array[size];
and than try to assign a value without specifying an index position:
array = '\0';
By doing:
array[index] = '0\';
You're specifying the accessible/modifiable address previously declared.