Can anyone explain why the if statement below never succeeds? I am running it as part of a Node.js v0.8.7 app.

js_forloop_wtf.js

var arr = ['a', 'b', 'c'];
 
for (i in arr) {
  if (i === 0) {
    console.log('do something special')
  }
}
 
// sadly, that console.log never happens

Uh, I'm guessing you mean to do i == 0 to match 'a' instead of i === 0. The difference is that == will try to do type coercion to transform 'a' into 0, but === will not.

Bacause this
var arr = ['a','b','c']; for(i in arr) console.log(typeof i);
shows
string string string
I think this is in operator giving strings as it is intended to list object keys.

You're right, but why isn't it an integer in the first place? Why is it "0", "1" and "2" instead of 0, 1 and 2?