Matias Figueroa matix
matix
/ 01-js-scoping-problem.js
Last active
June 1, 2022 21:46
— forked from anonymous/Array.forEach.js
Scoping and variable hoisting are two of the most challenging subjects to learn when picking up javascript, because it is fundamentally different from the other C-like languages' behavior. Javascript, unlike C and others, creates a new variables scope for each CLOSURE created, not for each BLOCK. This leads to some confusion in some cases. Here'…
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| var array = ["zero","first","second","third","fourth","fifth"]; | |
| var closures = []; | |
| for(var i=0, l=array.length; i<l; i++){ | |
| closures.push(function(){return array[i]}); | |
| } | |
| closures[3](); | |
| // Expected "third", but actually returns 'undefined', | |
| // because js did not create a separate scope for the "for" block |