Question

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Useful Regular Expression Tutorial

Hello,

I recently started coding in javascript.

I came across “Regular Expressions” while I’m searching (goolgling) to validate forms (name, email ID’s, etc.)

Can someone help this newbie coder by explaining:

1. What are regular expression?
2. How are they useful in programming?
3. Are they simple to understand?
4. Where can I get some good reference to learn these?

Any help is much appreciated.

Thank you!

Answer 1

1) what are regular expression

“A regular expression (regex or regexp for short) is a special text string for describing a search pattern. You can think of regular expressions as wildcards on steroids. You are probably familiar with wildcard notations such as *.txt to find all text files in a file manager. The regex equivalent is .*\.txt$.“

2) how are they useful in programming

Very.

3) Are they simple to understand

It depends. They can range from simple to understand to nearly unintelligible.

4) where can I get some good reference to learn these

This is a very good place to start: http://www.regular-expressions.info/