Using regular expressions in JavaScript

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What is a Regular Expression
A regular expression is a sequence of characters that forms a search pattern.

Let us understand the use of regular expressions with an example. The following strings contain words and numbers. From the string we want to extract all the numbers. Bsically the program should work with any string.

Mark-9 Tim-890 Sam-10 Sara-9902
Result : 9, 890, 10, 9902

908ABC12XYZ34
Result : 908, 12, 34

$1 $2 $901 ABC(100)
Result : 1, 2, 901, 100

Here is what we want the page to do
1. User enters the string in the first textbox
2. When "Process String" button is clicked, the numbers should be extracted from the string and displayed in the text area element.

It will be very complex and error prone if we have to achieve this without using regular expressions.

[input type="text" id="txtBox" style="width:250px" /]
[br /][br /]
[input type="button" value="Process String" onclick="processString()" style="width:250px" /]
[br /][br /]
[textarea id="txtArea" rows="4" cols="30"][/textarea]
[script type="text/javascript"]
function processString()
{
// Clear the textarea element
// Retrieve the user intput from the textbox
// Regular expression should be in 2 forward slashes //
// Letter g at the end of the regular expression performs a global match
// match() method returns all substrings that match the given regular expression

if (result != null) {
// Add the retrieved numbers to the textarea element
}
}
}
[/script]

[krutomjer]

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[DANJUMA]

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[fabianmadurai]

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[sunmustbedestroyed]

You helped me get through part of project I was stuck on. Thanks!

[Dynamic]

awesome job mate. set me upon the right path for my javascript validation

[Jethorus]

Omg thank you ! so clear and so helpful, i can already tell i will be watching all of your videos lol

[sourabhkulkarni]

one of the best tutorial on regular expression. god bless you.

[zenlogie]

I wish there were more instructors like you on youtube dear sir. All my respect!

[samdavepollard]

This was very helpful.
Thank You for sharing your knowledge.

[garrettbaker]

Excellent series...very helpful! Thanks!

[elkhanhamet]

Amazing tutorial sir!!! Thank you very much for your help!!!

[jaxparrow]

Thanks, man.
As always, great stuff!

[davidespada]

Thank you..
but can you make video for regular expression, to make a good understand of it.

[ConaxHateGG]

This is great, I always get confused by regular expressions!

[pancakesmister]

Thank you for your video! You rule! Thumps up!

[shaikarshad]

Awesome to have php vedio in your chanel...!

[getpwnd]

is there a cheat sheet of all reg exp?

[FernandoDiaz-lybr]

you're the best in the world!! :D

[cynthiamanor]

Thanks for posting! This answered a question I've been researching.

[yeahforsurebro]

Why would you use XHTML 1.0 instead of HTML5 for this tutorial :/ . I don't understand anything because of that.