finding the word at a position in javascript

Question

For string input of \'this is a sentence\' it must return \'is\' when position is 6 or 7. When position is 0, 1, 2, 3 or 4 result must be \'this\'.

What is the easie

Answer 1

var str = "this is a sentence";

function GetWordByPos(str, pos) {
    var left = str.substr(0, pos);
    var right = str.substr(pos);

    left = left.replace(/^.+ /g, "");
    right = right.replace(/ .+$/g, "");

    return left + right;
}

alert(GetWordByPos(str, 6));

P.S. Not tested throughly and no error handling yet.