Question

I need something to increment string values representing length (css margins)

the current solution is:

function incPx(a,b){
     return parseInt(a) + parseInt(b) +'px';
}
incPx($(el).css('margin-left'), '10px')

but there may be a jQuery thing for that maybe? to work with other units that ‘px’

Answer 1

Others have already suggested jQuery.css()‘s relative values, but keep in mind that you can easily use parseInt to convert a string like 50px to a Number, like so:

console.log(parseInt('50px', 10));
// 50

function incPx(a, b){
    a = parseInt(a, 10) || 0;
    b = parseInt(b, 10) || 0;
    return (a + b) +'px';
}​

Don’t forget to pass a radix of 10, though. More examples: Example: Using parseInt (MDN)