Eric Elliott eric at
Wed Mar 5 00:24:34 PST 2014

What ever happened to Array.prototype.contains? There's an old strawman for
Array.prototype.has ( ) that
references this thread: ( )

But it seems the thread fizzled out a couple years ago, and
Array.prototype.contains didn't seem to make its way into ES6. That seems
odd, since we do have String.prototype.contains, and it seemed like it was
desirable for DOM. It's also a standard utility function in several

Was it left out on purpose? If so, what was the justification?

I predict code like this without it:

''[1, 2, 3], 2);  // true

- Eric

Author, "Programming JavaScript Applications" (O'Reilly)
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