sstephenson/prototype — comment on commit 2f5b6338ab5bcdb393a4074c36af60ba4dc69af4
File: src/prototype/lang/array.js line 577
By jdalton:

Prototype's `Array#inject` does not behave identical to ES5 Array#reduce.

~~~ js
var count = 0; [1,2,3].reduce(function(sum, x) { count++ }), count; // 2
var count = 0; [1,2,3].inject(null, function(sum, x) { count++ }), count; // 3
~~~