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JS if inside for loop

Answer 1

+2 A:

You need to exit the loop on the first match so it doesn't continue until the end, like this:

jQuery.event.add(window, "load", resizeFrame);
jQuery.event.add(window, "resize", resizeFrame);
function resizeFrame() {
    for (x=232;x<=3000;x=x+226){
        if ($(window).width() < x ){
            $("#grid-content").css( 'width', x +'px' );
            break; //add this
        }
    }
}

You can optimize a bit though, like this:

jQuery(window).bind("load resize", function () {
    var w = $(window).width();
    for (var x=232;x<=3000;x+=226) {
        if (w < x ) {
            $("#grid-content").width(x);
            break;
        }
    }
});

Nick Craver 2010-10-14 01:05:09

+1 while @bobince showed a simpler solution, you correctly pointed out why his for loop fails.

galambalazs 2010-10-16 22:33:06

Answer 2

+6 A:

You don't need a loop to round-down-to-discrete-steps, it's simple arithmetic.

function resizeFrame() {
    var w= $(window).width();
    w-= (w-6) % 226;
    if (w<232) w= 232;
    $('#grid-content').width(w);
}

bobince 2010-10-14 01:20:39

Is it me, or does the expected result from OP's `if()` statement(s) seem out of sync with the expected result from the `for()` loop?

patrick dw 2010-10-14 01:31:19

@patrick: oh, good point, I hadn't spotted that! The round-down behaviour in the `if` does seem much more likely to be useful than rounding up. Changed answer to round down instead of up. (Also discarded the `3000` check since my guess is this and the 1136 limit in the `if` case are merely arbitrary upper bounds.)

bobince 2010-10-14 02:05:43

thanks. if you have the time could you explain this a little?

ThomasReggi 2010-10-14 04:12:53

`n-= n%chunk` is an idiom to round down to the nearest multiple of `chunk`. It uses the `%` operator to divide by `chunk` and take the remainder; subtracting the remainder from the original value leaves the rounded-down multiple. (The `-6` is needed to align the chunks so that they're at `6, 232, ...` instead of `0, 226, ...`.)

bobince 2010-10-14 12:10:48

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