Question

I have following line of code in javascript:

q && (c = q === "0" ? "" : q.trim());

WHat does it mean? I understand that c is equals either empty string or q.trim() result, but what does mean q && ()?

Answer 1

JavaScript optimizes boolean expressions. When q is false, the right hand side of the expression doesn’t matter for the result, so it’s not executed at all. So this is a short form of:

if( q ) {
    c = q === "0" ? "" : q.trim()
}