Php检查字符串格式是否正确

Looking for some help on how to validate a string in PHP.

My string contains:

• 4 NUMBER
• 1 LETTER
• 5 NUMBER

all in one entry, so like 1234A12345.

I need to make sure/validate this before inserting in the DB.

Can one of the wizard help me out there?

This is a pretty simple regex:

/^\d{4}[a-zA-Z]\d{5}$/

And in case you haven't used regex in PHP before.