Flags:
g : Globally matches everything
i : Ignore case
m : Match over multiple lines
MATCH
Matching is the basic use of regular expressions, learn this and the advanced stuff will be easy.
These following variation are to demonstrate ranges and quantities:
var str = "123456".match(/[0-9]{6}/g)
With this result: 123456
var str = "12345".match(/[0-9]{6}/g)
With this result: null
var str = "12345".match(/[0-9]{5,6}/g)
With this result: 12345
var str = "rabbit".match(/[a-z]{5,6}/g)
With this result: rabbit
var str = "Rabbit".match(/[a-z]{5,6}/g)
With this result: abbit
var str = "Rabbit".match(/[a-zA-Z]{5,6}/g)
With this result: Rabbit
Notice how this one is case insensitive:
var str = "Rabbit".match(/[a-z]{5,6}/gi)
With this result: Rabbit
var str = "B0bB1n5".match(/[a-zA-Z0-9]{7}/g)
With this result: B0bB1n5
Instead of using [A-Za-z0-9_] it's possible to use w instead:
var str = "B0bB1n5".match(/w{7}/g)
With this result: B0bB1n5
You can mix and match any which way you want:
var str = "12AB34CD".match(/[0-9]{2}[A-Z]{2}[0-9]{2}[A-Z]{2}/g)
With this result: 12AB34CD
var str = "12AB34CD".match(/[0-3]{2}[A-C]{2}[7-9]{2}[X-Z]{2}/g)
With this result: null
var str = "12AB89YZ".match(/[0-3]{2}[A-C]{2}[7-9]{2}[X-Z]{2}/g)
With this result: 12AB89YZ
EMAIL CHECKER
This bit of regex checks for a valid email. The 'i' at the finish makes this case insensitive:
var strValue = "a@b.com";
var objRegExp = /(^[a-z]([a-z_.]*)@([a-z_.]*)([.][a-z]{3})$)|(^[a-z]([a-z_.]*)@([a-z_.]*)(.[a-z]{3})(.[a-z]{2})*$)/i;
var x = objRegExp.test(strValue);
document.write(x);
With this result: true
REPLACE
Here's how to do a simple replace. The 'g' on the end tell's regex to match all occurrences:
var str = "I told you it'd be alright!".replace(/alright/g,'a problem');
And this is what str now contains: I told you it'd be a problem!
SPLIT
Split's are simple as well:
var myarray = "Let's make a list, or something?".split(/s/g)
Which results with: Let's,make,a,list,,or,something?
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