Read list by index in anonymous function not work in javascript

Asked Nov 02 '19 at 06:24

Active Nov 02 '19 at 06:24

Viewed 22 times

Please see the code below:

var l = [1,2,3,4]
var l2 = []
for (var i =0;i< l.length;i++) {
    l2.push( function () {alert(l[i])}   )
}


l2[0]()

what I expect is l2[0] will alert "1". But this is not working as I expected. It seems that the value of l is not read in the for-loop. And for my case, I do not want to pass any variables into the anonymous function. Is it possible to solve this?

asked Nov 02 '19 at 06:24

hengyue li

*what I expect is l2[0] will alert "1"* — It would, but you are using `i` not `0` and `i` is `4` after the loop – Quentin Nov 02 '19 at 06:38
1

change var to let .i.e. for (var i =0;i< l.length;i++) { ... } to for (let i =0;i< l.length;i++) { ... } – Joish Nov 02 '19 at 07:12
var -> let works for me. thanks – hengyue li Nov 02 '19 at 08:49

Read list by index in anonymous function not work in javascript

0 Answers0