格式化价格输入

Question

ideally this is for AS3, but I can always convert it down from JavaScript. Basically I want type numbers into a field and have it add the decimal. The issue is, the keyboard won't have a "." key

So if the final output was 10.45

it would automatically start to format as I type:

1 it would change to .01. And as I keep typing.. .01
.10
10.40 10.45

Answer 1

This can be accomplished by some simple string manipulation. Just split the string into parts and insert the decimal.

HTML

<input type="text" id="price" onchange="formatPrice(this)" />

Javascript

function formatPrice(obj) {
    //remove any existing decimal
    p = obj.value.replace('.','');

    //get everything except the last 2 digits
    var l = p.substring(-2, p.length-2);

    //get the last 2 digits
    var r = p.substring(p.length-2,p.length);

    //update the value
    obj.value = l + '.' + r;
}

You can see it working here: https://jsfiddle.net/x3wey5uk/