JavaScript setTimeout can't access function variable
javascript, settimeout
Solution
Actually people array is ok. What it happens is that your i is actually 2 and there is no third element in the array. That's why you get this error. Here is the solution:
function MyFunc() {
var people = Array({name: 'Alex', age: 25}, {name: 'Ellen', age: 43});
for (var i=0; i<people.length; i++) {
(function(i) {
setTimeout(function() {
ShowIt(people[i].name)
}, 1000);
})(i);
}
}
function ShowIt(name) {
console.log(name);
}
MyFunc();
Here is a jsfiddle http://jsfiddle.net/krasimir/XDfLu/2/
The long answer: when you use setTimeout you are passing a function to it. That function is called in the future and the things which you make there are also executed in the future. At that moment (the future one) your i is no longer 0 or 1. It is actually 2 because your loop ended. The provided solution uses additional closure to create one more scope/context. And once the function passed to setTimeout is called it looks for a i variable. There is no such a thing in its scope, so it goes one level up. And there is the actual value which we need.
Problem
At least is what I think it happens in this case: ``` function MyFunc() { var people = Array({name: 'Alex', age: 25}, {name: 'Ellen', age: 43}); for (var i=0; i<people.length; i++) { setTimeout(function() { ShowIt(people[i].name) }, 1000); // !!! } } function ShowIt(name) { alert(name); } ``` I get this error `Uncaught TypeError: Cannot read property 'name' of undefined`, so it looks like inside the `setTimeout` listener function the `people` variable is not accessible. Why and how can I fix it?