Regex for match following strings

Question

I am new to regex I want to create regex for following

AL--->accepted
AL100--->accepted
100---->accepted
100L--->Rejected
AL1122--->accepted
AL1224K-->rejected

Means either its AL or AL with numbers or only numbers

Below is my Regex which I have written but it's not working

^AL[0-9]+$|AL

Please Help

Thanks

Tim Biegeleisen · Accepted Answer · 2016-12-16 07:11:16Z

2

I think you can just slightly modify the regex you already have to this:

^AL[0-9]*$

This will match AL in isolation (no digits), or followed by any number of digits, but nothing else.

Demo:

/^AL[0-9]*$/.test('AL1224K');
false

/^AL[0-9]*$/.test('AL1224');
true

Update:

If you also want to accept pure numbers, then you can modify your regex by making the leading AL optional:

^(AL)?[0-9]*$

E.g.

/^(AL)?[0-9]*$/.test('AL1224')
true
/^(AL)?[0-9]*$/.test('1224')
true

answered Dec 16, 2016 at 6:13

Tim Biegeleisen

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2 Comments

Hey what if i have to make number also to be expected /^AL[0-9]*$/.test('100');

If an empty string is not expected, use ^(AL[0-9]*|[0-9]+)$