Javascript – How to change lowercase chars to uppercase using the ‘keyup’ event

javascriptjquery

My goal is to use the jQuery event .keyup() to convert inputted lowercase chars to uppercase.

How can I achieve this?

Plain ol' javascript:

var input = document.getElementById('inputID');

input.onkeyup = function(){
    this.value = this.value.toUpperCase();
}

Javascript with jQuery:

$('#inputID').keyup(function(){
    this.value = this.value.toUpperCase();
});

In JavaScript, everything is 'truthy' or 'falsy', and for numbers 0 means false, everything else true. So you could write:

if ($(selector).length)

You don't need that >0 part.

The jQuery constructor accepts a 2nd parameter called context which can be used to override the context of the selection.

jQuery("img", this);

Which is the same as using .find() like this:

jQuery(this).find("img");

If the imgs you desire are only direct descendants of the clicked element, you can also use .children():

jQuery(this).children("img");