Actionscript: Regular expression for file type checking

Question

I want to check the file extension from the string using regular expression in action script.

By googling, I find this, but I'm week to regular expression.

Thanks.

Answer 1

This regex is more reliable than the given example:

  ^[^\\?\/%*:|"><]+\.([^\\?\/%*:|"><]*)$

You can refer to the file extension as $1 if you refer to it in replacement part.

You can refer to the file extension as \1 if you refer to it in search part.

Explanation

• ^ Assert position at the beginning of a line.
• [^\\?\/%*:|"><]+\. Matches any character except \, ?, /, %, *, :, |, ", >, <, at least one character, until the last . character.
• ([^\\?\/%*:|"><]*) Matches any character except \, ?, /, %, *, :, |, ", >, <, as many as possible or none, and capture the bracketed part as group number 1.
• $ Assert position at the end of a line.