Question

I’m creating simple form validation that excludes any entries that have a letter in them (basically anything from a-z or A-Z).

This is what I am currently using but my script only rejects anything that isn’t 0-9. which will reject periods, brackets and dashes which I want to validate.

var numericReg = /^\d*[0-9](|.\d*[0-9]|,\d*[0-9])?$/;
    if(number != "" && !numericReg.test(number)) {
    return false;

How can I check for letters only?

Another way to do this would be to only accept inputs that have numbers 0-9, and the following characters: “.”, “-“, “(“, “)”

Answer 1

Two regular expressions for you to try. The first matches strings that only contain the characters you specified. The second matches strings that contain no letters a-z or A-Z:

var isPhoneChar = /^[-.() \d]+$/;
var isNonAlpha = /^[^a-z]+$/i;

Keep in mind, isNonAlpha won’t protect against ñüṃȅɍǒǘṩ ȯẗḥḛṝ ḽëʈťĕřś‼

You may consider also allowing x for phone ex̲tensions and + for international dialing.