Strangest language feature - Stack Overflow | Hacker News Reader

Strangest language feature - Stack Overflow

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9 pointsniyazpk6 comments

Here is my 2cents on top of all those!

This is a valid for-loop in JavaScript

     for (;;) {}

(Saw it for the first time in Crockford's jsLint)

What can it be used for?

It's equivalent to

  while (1) {...}

and I've heard it referred to as a "forever" loop. It's a natural consequence of each term of the for being optional---skip the init and/or the update, and nothing happens, skip the test and it just always evaluates to true.

It is actually a forever/infinite loop unless you break out of it with code like this:

    var i = 0;
    for (;;) {
      log(i);
      i++;
      if (i > 10) {
        break;
      }
    };

In a way is recursion, it is equivalent to this:

    var i = 0;
    (function () {
       log(i);
       i++;
       if (i > 10) {
         return;
       }
      arguments.callee();
    })();

It's valid in C and other related languages, too.

How about in C int i=1; int * p = &i; int x = 100/* p; doesn't even compile (why?)

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