I have a javascript function:
function myFunction(value1,value2,value3)
{
//Do stuff and
value2=somevalue2 //to return
value3=somevalue3 //to return
}
function call in Code: ....
myFunction("1",value2,value3);
if(value2 && value3)
{
//Do some stuff
}
in this scenario how to pass value2 and value3 to the called method or how to return values in Java script.
This question is related to
javascript
The answers cover things very well. I just wanted to point out that the mechanism of out parameters
, as described in the question isn't very javascriptish. While other languages support it, javascript prefers you to simply return values from functions.
With ES6/ES2015 they added destructuring that makes a solution to this problem more elegant when returning an array. Destructuring will pull parts out of an array/object:
function myFunction(value1)
{
//Do stuff and
return [somevalue2, sumevalue3]
}
var [value2, value3] = myFunction("1");
if(value2 && value3)
{
//Do some stuff
}
It's difficult to tell what you're actually trying to do and if this is what you really need but you might also use a callback:
function myFunction(value1,callback)
{
//Do stuff and
if(typeof callback == 'function'){
callback(somevalue2,somevalue3);
}
}
myFunction("1", function(value2, value3){
if(value2 && value3)
{
//Do some stuff
}
});
Javascript is duck typed, so you can create a small structure.
function myFunction(value1,value2,value3)
{
var myObject = new Object();
myObject.value2 = somevalue2;
myObject.value3 = somevalue3;
return myObject;
}
var value = myFunction("1",value2,value3);
if(value.value2 && value.value3)
{
//Do some stuff
}
I would prefer a callback solution: Working fiddle here: http://jsfiddle.net/canCu/
function myFunction(value1,value2,value3, callback) {
value2 = 'somevalue2'; //to return
value3 = 'somevalue3'; //to return
callback( value2, value3 );
}
var value1 = 1;
var value2 = 2;
var value3 = 3;
myFunction(value1,value2,value3, function(value2, value3){
if (value2 && value3) {
//Do some stuff
alert( value2 + '-' + value3 );
}
});
function myFunction(value1,value2,value3)
{
return {val2: value2, val3: value3};
}
The return statement
stops the execution of a function and returns a value
from that function.
While updating global variables is one way to pass information back to the code that called the function
, this is not an ideal way of doing so. A much better alternative is to write the function so that values that are used by the function are passed to it as parameters and the function returns whatever value that it needs to without using or updating any global variables
.
By limiting the way in which information is passed to and from functions we can make it easier to reuse the same function from multiple places in our code.
JavaScript provides for passing one value back to the code that called it after everything in the function that needs to run has finished running.
JavaScript passes a value from a function back to the code that called it by using the return statement
. The value to be returned is specified in the return
keyword.
Its very simple. Call one function inside another function with parameters.
function fun1()
{
var a=10;
var b=20;
fun2(a,b); //calling function fun2() and passing 2 parameters
}
function fun2(num1,num2)
{
var sum;
sum = num1+num2;
return sum;
}
fun1(); //trigger function fun1
Source: Stackoverflow.com