Question

I am quite new to JavaScript, and so am still coming into small things that I don’t quite understand and don’t seem to appear when I search for them.
Please could somebody point me out what the ? : syntax is doing below.

var chCode = ('charCode' in event) ? event.charCode : event.keyCode;

Answer 1

This is called the ternary operator. It’s a short if...else statement.

Basically, your code can be expanded to this.

var chCode;

if ('charCode' in event) {
    chCode = event.charCode;
} else {
    chCode = event.keyCode;
}