Regular expression for no more than two repeated letters/digits

Question

I have a requirement to handle a regular expression for no more than two of the same letters/digits in an XSL file.

• no space
• does not support special

Answer 1

Does this one work for you?

/(\b(?:([A-Za-z0-9])(?!\2{2}))+\b)/

Try it out:

var regex = new RegExp(/(\b(?:([A-Za-z0-9])(?!\2{2}))+\b)/)
var tests = ['A1D3E', 'AAAA', 'AABAA', 'abccddeeff', 'abbbc', '1234']

for(test in tests) {
   console.log(tests[test] + ' - ' + Boolean(tests[test].match(regex)))
}

Will output:

A1D3E - true
AAAA - false
AABAA - true
abccddeeff - true
abbbc - false
1234 - true