Limiting the times that .split() splits, rather than truncating the resulting array

Question

Really, pretty much what the title says.

Say you have this string:

var theString = \"a=b=c=d\";

Now, when you run theString

Answer 1

If you want the exact equivalent of the Java implementation (no error checking or guard clauses etc):

function split(str, sep, n) {
    var out = [];

    while(n--) out.push(str.slice(sep.lastIndex, sep.exec(str).index));

    out.push(str.slice(sep.lastIndex));
    return out;
}

console.log(split("a=b=c=d", /=/g, 2)); // ['a', 'b', 'c=d']

This has the added benefit of not computing the complete split beforehand, as you mentioned in your question.