| : or meaning, means that you want to match the keywords for multiple, and are all you want such as: Var str= ' 17 Chinese ships near Mahkota Reef are under the supervision of the Philippine Army ' var re =/Philippines | China ship | under surveillance/g; Str.replace (Re,function (str) {} * * * * 17 * * * * * * * * * * * * * * * * * * * * * * * * * *//Match subkey: Parenthesis () (another meaning, grouping operation)
1+1*2//(+) *//The whole of the regular is called (mother)//And then the first parenthesis inside the left is called the first child (mother's first child)//The second parenthesis is the second child var str = ' 2013-6-7 ';
var re =/(\d+) (-)/g;
str = str.replace (re,function ($0,$1,$2) {///First parameter: $ A (mother), second parameter: $ (first child)//, second parameter: $ (second child) alert ($); Alert ($); Alert ($); return + '. '; Return $0.substring (0,$0.length-1) + '. '; }); The first alter pops up "2013-" the second pop-up "6-" where the first of the $2013 is $6 for the second time-this is the meaning of the match subkey var str = ' abc ';
var re =/(a) (b) (c)/;
Alert (Str.match (re)); [Abc,a,b,c] (can get a collection of children when match does not have G)
var kwords=str.match (REG);
1. reg does not add G,match also only find the first one
When to use: when you want to get the content and location of the first keyword
Return value: An array that contains the contents of the Found keyword
kwords:["keywords"]
kwords.index-> keyword location if not found, return to null!
2. Reg Plus G,match will find the contents of all the keywords
When to use: when you want to get the content of all your keywords
Return value: An array that contains the contents of all the keywords
The length property of the array, which records the number of all keywords
Cons: Only the content of all keywords can be found, the location of each keyword cannot be found.
Emphasis: As long as you use match, you can return NULL, you must first determine that it is not NULL, and then perform subsequent operations!
//. : Any character//\. : The real point
/*var str = ' A.C ';
var re =/a\.c/;
Alert (Re.test (str)); */
\b: Independent part (start, end, space)//\b: Non-independent part
var str = ' Onetwo ';
var re =/one\b/;
Alert (Re.test (str)); var re =/sclass/; When you need to pass the argument, be sure to use the full name of the var re = new RegExp (' \\b ' +sclass+ ' \\b '); Note that the full name needs to be escaped.//\1: Duplicate First subkey//\2: Duplicate Second subkey
/*var str = ' ABCA ';
var re =/(a) (b) (c) \2/;
Alert (Re.test (str)); */
/*var re =/\w\w/; C9var re =/(\w) \1/; CC 99
The regular in JS
