JavaScript regular Expressions (top)

Regular expressions are generally used to validate client input, while server-side PHP, ASP. NET and other scripts no longer need to be verified, saving the background overhead.

1. Two ways to create

var box=new RegExp ("box", IG); The second argument is a pattern modifier, I means ignoring case, and G is a global match

var box=/box/i;

2. Matching method

(1) Test: Tests if the string matches.

var pattern =new RegExp ("box", I);

var str= "box"; Str= "This is a box! ", also returns true

Alert (Pattern.test (str)); Returns True

　　

(2) Exec: Returns the matching array.

var pattern =new RegExp ("box", I);

var str= "box";

Alert (pattern.exec (str));

Note: There are other applications for exec, which will be mentioned later.

3. Regular expression methods that use strings

(1) match (pattern):

var pattern = "Box/ig";//Turn on global

var str= "This is a box! That's a box! "

Alert (Str.match (pattern)); return array [Box,box]

(2) Replace (pattern,replacement): Replace matching elements

var pattern = "box/i";

var str= "This is a box! That's a box! "

Alert (str.replace (Pattern, "Tom")); Returns a tom! That's a box!

(3) Search (pattern): Find the first matching position without the need for a global

(4) Split (pattern): Split into arrays by regular expression

　　

JavaScript regular Expressions (top)