Question

I have a form that I’m trying to automatically enforce decimals in some of the input fields. Basically I would like for the users to not worry about format, but simply have the fields format themselves onBlur.

Here are a few examples of what I’m hoping to achieve:

1.) If a user enters “0.95” nothing is done, because this is the ultimate format I’m going for in the end.

2.) If a user enters “.95” I would like for the field onBlur to change to the above format “0.95”. (likewise if they enter “.9” etc)

I have been scouring around on the internet all night long looking for a solution, so this is my last resort! Any help and feedback I can get would be more than appreciated!

Thank you!

Answer 1

This is nice and concise:

function blurFormatDecimal (e) {
    var val = isFinite(this.value) ? +this.value : 0;
    this.value = val.toFixed(2);
}
myInput.onblur = blurFormatDecimal;

Use isFinite() instead of !isNaN() because isNaN("Infinity") returns false, but you certainly don’t want to accept "Infinity" as valid input.

http://jsfiddle.net/gilly3/NjeQD/