PHP regular expression to match exact string

Question

I have string like "ABC 1000", "ABC 1", "ABC 100".

In above string example, first 3 character ie ABC is fixed every time and then digits, digits can be long upto N numbers.

In 2nd part ie after "ABC " it should always be numberic value, no alphabet, no special symbol.

So, how can I manage with regular expression. Please help.

I have tried with following but failed ..

$var="ABC 100";

preg_match("/^INR /[0-9]+/", $var)

Answer 1

You have an extra / in your regular expression. It should be:

preg_match('/^ABC \d+/', $var);

Answer 2

You could use this:

^[A-Za-z]{3} *\d+$

http://regex101.com/r/gE4mS4

$var="ABC 100";
preg_match("/^[A-Za-z]{3} *\d+$/", $var)

• 3 letters (case insensitive)
• 0 or more space
• 1 or more digits