How can i use external variables in "setInterval" code?

Lagon666

When i run this functions it says the count is undefined.

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function hello(){

    var count = 0;

    var timer = setInterval('count+=1;alert(count);',2000);

}

Dormilich

some functions change the variable scope. setInterval() and setTimeout() will have global scope and because count was defined inside a function, count will have the function's local scope and not the global one. thus count is undefined (on global scope).

to work around that you need two things, a function for the code to execute and a closure to preserve the values.

(will be back when I got more time…)

rnd me

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function hello(){

    var count = 0;

    var timer = setInterval( function(){  count+=1;alert(count); },2000);

}

Dormilich

some articles about closures:
JavaScript Closures for Dummies
JavaScript Closures 101
JavaScript Closures

and some about Scope
Scope in JavaScript
Explaining JavaScript Scope and Closures

How can i use external variables in "setInterval" code?

re: How can i use external variables in "setInterval" code?

re: How can i use external variables in "setInterval" code?

re: How can i use external variables in "setInterval" code?

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