Calling functions inside JavaScript 'for' loops

Question

I want to call multiple functions in a JavaScript 'for' loop, but they are only being called the first time and the loops terminates.

I have tried making the functions unique, by passing a value to them, using some generic function caller such as:

for(i=0; i<50; i++){
    alert('test');
    generator_function(i);
}


function generator_function(variable){
   function1(variable);
   function2(variable);
   function3(variable);
   function4(variable);
   var sum = local_array.reduce(function(a, b) { return a + b });
   var avg = sum / local_array.length;
}

Which seems to work, but the local arrays still hold the elements from the first loop.

Is there a better way of calling a collection of functions inside a loop? I have global arrays which are being altered in these loops and am wondering if they need to be local, i.e. inside the functions somehow?

one possible problem is for(i=0; i<50; i++){ here i is a global variable if inside any one of the function(where i is again in global scope) is value is changed to > 50 then the loop will get terminated. Try for( var i=0; i<50; i++){ instead — Arun P Johny
– Arun P Johny, Commented Aug 22, 2013 at 10:18
To be sure: You can see only one alert? If so, there might be an error occured when executing one of the functions in generator_function. Have you checked the console, there should be an error message. — Teemu
– Teemu, Commented Aug 22, 2013 at 10:21
The functions work fine on their own. I think @Arun may be right in talking about the local variable in the loops. I had a lot of those and wondered why you needed the 'var'. I will run a few tests but feel free to put that as an answer. — Jon
– Jon, Commented Aug 22, 2013 at 10:25

Arun P Johny · Accepted Answer · 2013-08-22 10:27:31Z

2

one possible problem is for(i=0; i<50; i++){ here i is a global variable if inside any one of the function(where i is again in global scope) is value is changed to > 50 then the loop will get terminated they both references the same instance in the global scope. Try for( var i=0; i<50; i++){ instead.

When you use var in a variable declaration, that variable will be created in the local scope(the function in which it is declared)

answered Aug 22, 2013 at 10:27

Arun P Johny

389k68 gold badges532 silver badges532 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Calling functions inside JavaScript 'for' loops

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related