WordWrap //JavaScript Function (See related posts)

This is very clever, if unreadable. But I think it has a bug in it, since the

j.input.length + (j = s.substr(m).match(/^\S*/)).input.length + j[0].length

clause is not functionally different than

j.input.length + (j = s.substr(m).match(/^\S*/)).input.length

as you're substr-ing a string length greater than the string itself. Javascript doesn't complain of course, but this is wrong.

Furthermore, this very complicated clause is written more comprehensibly as

m + (j = s.substr(m).match(/^\S*/)).input.length

sincec j.input.length is always just m.

This, in turn, is equivalent to
s.length

In other words, I think this whole clause is a waste of code.

On another note, I needed a word wrap function that will wrap at spaces if possible AND break-up any words longer than m. Neither values of c (true or false) as paramters to your function will result in this since although c=true will breakup single words longer than m, it doesn't wrap at word boundaries where this is possible, and will break up words shorter than m. I can't imagine anyone wanting word-wrap functionality along these lines! I rewrote your function to generate the output I want:
"My word is biiiiiiiiiiiiiiig" => "My word is\nbiiiiiiiii\niiig"

Here is the function:

String.prototype.wordWrap = function(m, b, c){
    var i, j, s, r = this.split("\n");
    if(m > 0) for(i in r){
        for(s = r[i], r[i] = ""; s.length > m;
            j = c ? m : (j = s.substr(0, m).match(/\S*$/)).input.length - j[0].length
            || m,
            r[i] += s.substr(0, j) + ((s = s.substr(j)).length ? b : "")
        );
        r[i] += s;
    }
    return r.join("\n");
};

I.e., just replace your mysterious clause with m.

hi! everybody your "clever but unreadable code" does'nt seem to work for the strings like qqqqqqqqqqqqqqqq...and longer ones....it wraps this string like this qqqqqq qqqqqqq qqqqqqqqq ...i.e with spaces...please find a better solution but quickly....

Hi, I didn't checked comments on my codes for a long time, so I'll answer :)

@susan12345
Here it's working fine my code version...

document.write("qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq".wordWrap(10, "
"));

And

document.write("qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq".wordWrap(10, "
", true));



@nkallen
If I did all those things, there must be a reason, normally I don't make duplicated code, so that was the reason, test the above 2 lines with your version.

It replaced my br tag aaaaaaa, I won't try to post "& lt ;" (maybe it work: <) xD

alert("qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq".wordWrap(10, "\n", true));

alert("qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq".wordWrap(10, "\n", true));

AAAAAAAAAAAAAAAAAAAAAAAAAA

alert("qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq".wordWrap(10, "\n"));