Regex for exactly 6 char, first must be a letter
What is the regex that matches these examples(6 characters, first is a letter, others are numbers):
u78945 - valid
s56123 - valid
456a12 - invalid
78561d - invalid
1234567 - invalid
i don't know if regular expressions are the same for every programming language. I need it for Regular Expression Validator control using VB ASP.NET.
Use this pattern:
^[a-z][0-9]{5}$
This will match any Latin letter (lower-case unless using case-insensitive matching) followed by 5 decimal digits.
Note: You could use d instead of [0-9] , but read this for an explanation about why they are different.
[a-zA-Z]d{5}
If you are searching explicitly from the beginning of the line use ^
^[a-zA-Z]d{5}
and append $ for the end of the line.
^[a(?i)-z(?i)]d{5}$
The (?i ) code enables the expression to accept any letter without case-sensitivity. The d{5} looks for a sequence of numbers whose length is exactly 5.