Regular expression to allow alphanumeric, only one space and then alpahnumeric

Question

I've searched and searched and tried many different ways, but I can't seem to figure this out. I'm looking for a way to only allow alphanumeric characters, then only one space, then alphanumeric characters. I'm sure it's easy, but I don't know it.

Examples of what I want:

    First Last     Allowed
    First La-st    Not Allowed
    FirstLast      Not Allowed
    First  Last    Not Allowed
    First La'st    Not allowed

I'd then like to remove the invalid characters from the string.

Please let me know if you need more information. Thanks a lot!

Answer 1

^[a-zA-Z0-9]+ [a-zA-Z0-9]+$

… should do it.

Answer 2

This should do it:

^[0-9a-zA-Z]+ [0-9a-zA-Z]+$

Demo: http://jsfiddle.net/5m6RH/

Answer 3

Use this regex:

^[\p{L}\d]+ [\p{L}\d]+$