I'm trying to push to a two-dimensional array without it messing up, currently My array is:
var myArray = [
[1,1,1,1,1],
[1,1,1,1,1],
[1,1,1,1,1]
]
And my code I'm trying is:
var r = 3; //start from rows 3
var c = 5; //start from col 5
var rows = 8;
var cols = 7;
for (var i = r; i < rows; i++)
{
for (var j = c; j < cols; j++)
{
myArray[i][j].push(0);
}
}
That should result in the following:
var myArray = [
[1,1,1,1,1,0,0],
[1,1,1,1,1,0,0],
[1,1,1,1,1,0,0],
[0,0,0,0,0,0,0],
[0,0,0,0,0,0,0],
[0,0,0,0,0,0,0],
]
But it doesn't and not sure whether this is the correct way to do it or not.
So the question is how would I accomplish this?
This question is related to
javascript
arrays
for-loop
multidimensional-array
push
The solution below uses a double loop to add data to the bottom of a 2x2 array in the Case 3. The inner loop pushes selected elements' values into a new row array. The outerloop then pushes the new row array to the bottom of an existing array (see Newbie: Add values to two-dimensional array with for loops, Google Apps Script).
In this example, I created a function that extracts a section from an existing array. The extracted section can be a row (full or partial), a column (full or partial), or a 2x2 section of the existing array. A new blank array (newArr) is filled by pushing the relevant section from the existing array (arr) into the new array.
function arraySection(arr, r1, c1, rLength, cLength) {
rowMax = arr.length;
if(isNaN(rowMax)){rowMax = 1};
colMax = arr[0].length;
if(isNaN(colMax)){colMax = 1};
var r2 = r1 + rLength - 1;
var c2 = c1 + cLength - 1;
if ((r1< 0 || r1 > r2 || r1 > rowMax || (r1 | 0) != r1) || (r2 < 0 ||
r2 > rowMax || (r2 | 0) != r2)|| (c1< 0 || c1 > c2 || c1 > colMax ||
(c1 | 0) != c1) ||(c2 < 0 || c2 > colMax || (c2 | 0) != c2)){
throw new Error(
'arraySection: invalid input')
return;
};
var newArr = [];
// Case 1: extracted section is a column array,
// all elements are in the same column
if (c1 == c2){
for (var i = r1; i <= r2; i++){
// Logger.log("arr[i][c1] for i = " + i);
// Logger.log(arr[i][c1]);
newArr.push([arr[i][c1]]);
};
};
// Case 2: extracted section is a row array,
// all elements are in the same row
if (r1 == r2 && c1 != c2){
for (var j = c1; j <= c2; j++){
newArr.push(arr[r1][j]);
};
};
// Case 3: extracted section is a 2x2 section
if (r1 != r2 && c1 != c2){
for (var i = r1; i <= r2; i++) {
rowi = [];
for (var j = c1; j <= c2; j++) {
rowi.push(arr[i][j]);
}
newArr.push(rowi)
};
};
return(newArr);
};
Iterating over two dimensions means you'll need to check over two dimensions.
assuming you're starting with:
var myArray = [
[1,1,1,1,1],
[1,1,1,1,1],
[1,1,1,1,1]
]; //don't forget your semi-colons
You want to expand this two-dimensional array to become:
var myArray = [
[1,1,1,1,1,0,0],
[1,1,1,1,1,0,0],
[1,1,1,1,1,0,0],
[0,0,0,0,0,0,0],
[0,0,0,0,0,0,0],
[0,0,0,0,0,0,0],
];
Which means you need to understand what the difference is.
Start with the outer array:
var myArray = [
[...],
[...],
[...]
];
If you want to make this array longer, you need to check that it's the correct length, and add more inner arrays to make up the difference:
var i,
rows,
myArray;
rows = 8;
myArray = [...]; //see first example above
for (i = 0; i < rows; i += 1) {
//check if the index exists in the outer array
if (!(i in myArray)) {
//if it doesn't exist, we need another array to fill
myArray.push([]);
}
}
The next step requires iterating over every column in every array, we'll build on the original code:
var i,
j,
row,
rows,
cols,
myArray;
rows = 8;
cols = 7; //adding columns in this time
myArray = [...]; //see first example above
for (i = 0; i < rows; i += 1) {
//check if the index exists in the outer array (row)
if (!(i in myArray)) {
//if it doesn't exist, we need another array to fill
myArray[i] = [];
}
row = myArray[i];
for (j = 0; j < cols; j += 1) {
//check if the index exists in the inner array (column)
if (!(i in row)) {
//if it doesn't exist, we need to fill it with `0`
row[j] = 0;
}
}
}
you are calling the push() on an array element (int), where push() should be called on the array, also handling/filling the array this way makes no sense you can do it like this
for (var i = 0; i < rows - 1; i++)
{
for (var j = c; j < cols; j++)
{
myArray[i].push(0);
}
}
for (var i = r; i < rows - 1; i++)
{
for (var j = 0; j < cols; j++)
{
col.push(0);
}
}
you can also combine the two loops using an if condition, if row < r, else if row >= r
var r = 3; //start from rows 3
var c = 5; //start from col 5
var rows = 8;
var cols = 7;
for (var i = 0; i < rows; i++)
{
for (var j = 0; j < cols; j++)
{
if(j <= c && i <= r) {
myArray[i][j] = 1;
} else {
myArray[i][j] = 0;
}
}
}
Create am array and put inside the first, in this case i get data from JSON response
$.getJSON('/Tool/GetAllActiviesStatus/',
var dataFC = new Array();
function (data) {
for (var i = 0; i < data.Result.length; i++) {
var serie = new Array(data.Result[i].FUNCAO, data.Result[i].QT, true, true);
dataFC.push(serie);
});
In your case you can do that without using push
at all:
var myArray = [
[1,1,1,1,1],
[1,1,1,1,1],
[1,1,1,1,1]
]
var newRows = 8;
var newCols = 7;
var item;
for (var i = 0; i < newRows; i++) {
item = myArray[i] || (myArray[i] = []);
for (var k = item.length; k < newCols; k++)
item[k] = 0;
}
You have to loop through all rows, and add the missing rows and columns. For the already existing rows, you loop from c to cols, for the new rows, first push an empty array to outer array, then loop from 0 to cols:
var r = 3; //start from rows 3
var c = 5; //start from col 5
var rows = 8;
var cols = 7;
for (var i = 0; i < rows; i++) {
var start;
if (i < r) {
start = c;
} else {
start = 0;
myArray.push([]);
}
for (var j = start; j < cols; j++) {
myArray[i].push(0);
}
}
Source: Stackoverflow.com