JS Regular Expression

JS Regular Expression

Time: 2016-04-20-10:44:47

Author: zhongxia

Regular expressions are a very common knowledge point in JS verification. Validation of various forms, string validation, and so on can be quickly implemented using regular expressions

The usual way

Example: Verifying the ZIP code

function Ispostcode (str) {
var re =/^\d{6}$/;//different validation, using different regular expressions, as for cue information, you can customize
return re.test (str);
}

ispostcode (' 1231231 ') false
Ispostcode (' 123412) TrueSyntax for regular expressions

2. var reg = new RegExp(‘zhongxia‘,‘i‘)Whether it contains zhongxia, case insensitive

   Parameter 1: matching string parameter 2: Matching option flag: I case-insensitive G global search m multi-line lookup

4. Of course, there's another way to define regular expressions.var reg = /a/i
6. A few common methods:
   1. Test returns TRUE,FALSE, checksum, most commonly used
   2. EXEC mismatch returns null
   3. Match
   4. Replace
   5. Search does not match return-1
   6. Split
8. Metacharacters must be transferred with meta characters: ( [ { \ ^ $ | ) ? * + . var re =/?/(Error)
   var re =/\?/(Yes)
10. Use the RegExp constructor with the regular expression literal to create a regular expression note the point var str = "\?";
    alert (str);//Output only?
    var re =/\?/;//will match?
    Alert (Re.test (str));//true
    Re = new RegExp ("\?"); /error because this is equivalent to re =/\?/
    Re = new RegExp ("\ \"); /correct, will match?
    Alert (Re.test (str));//true

11. Commonly used/^start///caret (^) to represent the starting position of a character
    /start$///$ indicates where the character ends

    Determine if the character entered is an English lettervar reg=/^[a-zA-Z]+$/;

    Determines whether the input character is an integervar reg=/^[-+]?\d*$/;

    Determine if the character entered is: a-z,a-z,0-9var reg=/^[a-zA-Z0-9_]+$/;

    Determines whether the character entered is in Chinesevar reg=/^[\u0391-\uFFE5]+$/;

    Determine if the input email format is correctvar reg=/^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/;

    Determine if the input ZIP code (six-bit only) is correctreg=/^\d{6}$/;

    Phone:/^ ((\d{2,3}) | ( \d{3}-))? ((0\d{2,3}) |0\d{2,3}-)? [1-9]\d{6,7} (-\d{1,4})? $/

    Mobile:/^ (((\d{2,3)) | ( \d{3}-))? 13\d{9}$/

    URL:/^http:\/\/[a-za-z0-9]+. [a-za-z0-9]+[\/=\?%-&_~ ' @[]\ ': +!] ([^<>\ "\"])$/

    Idcard:/^\d{15} (\d{2}[a-za-z0-9])? $/

    QQ:/^[1-9]\d{4,8}$/

    Some special amount:/^ ((\d{1,3} (, \d{3}) | ( \d+)) (. \d{2})? $///Description: Except for "XXX xx,xxx xx,xxx.00" format

JS Regular Expression