JavaScript Basics-Regular Expressions

Overview

Regular expressions are used to retrieve and replace text that conforms to a pattern

Standard Regular Expression syntax

　　

JavaScript support for regular expressions

　　

Alternative notation

　　Reverse Surround

// requirement: Replace mpre.cnsuning.com to ${pre}, res.mpre.cnsuning.com not replace // implementation: JS does not support reverse loop sequence, using multiple matching " http://mpre.cnsuning.com/REShttp://res.mpre.cnsuning.com ". Replace (/[^\.) Mpre\.cnsuning/g,function ($1) {    return $1. Replace ('  mpre.cnsuning','${pre}')})

　　Named captures

Using index capture to circumvent

intersection and set difference set　　　

// JS does not support intersection and set difference set, still can only use multiple matches // /[a-d[m-p]]/:  can use ' | ' Alternative var reg =/[a-d]| [m-p]/; // intersection: [A-z&&[def]], the difference set is the same var reg1 =/([A-z])/,REG2 =/([def])/; var ' D '  && reg2.test (str);

　　Condition matching

Ditto, with multiple matches

　　　　

　　　　

JavaScript Basics-Regular Expressions