Question

I am trying for a regular expression for below requirement.

1. Total string length must be 3 or 4.
2. First two characters must be from a-z or A-Z
3. Last two characters must be from 0-9

I have tried the below, but I know this is not the good way

     var str = /^[a-zA-Z]{1,2} + [0-9]{2} + $/,   

Please help me on this.

Answer 1

var str = /^([a-z]{1,2}|[A-Z]{1,2})[0-9]{2}$/;

Then you test it as:

str.test("aa3"); // false, 2 integers are required
str.test("a34"); // true
str.test("aA33"); // false, 2 first characters have to be in the same case

Not sure what you really mean by First two characters must be from a-z or A-Z, if you want those characters to be the same cases, use the regex above, otherwise

var str = /^[a-zA-Z]{1,2}[0-9]{2}$/;