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  • 正则常用方法test,match,search,replace

    test:
    reg.test(str) 找到返回true,否则false 找到第一个后就会停止向后找

    let str = 'bacdera';
    let reg = /a/;
    console.log(reg.test(str))   =>true
    

    match:
    str.match(reg) 不匹配返回null ,匹配到就返回对应的数组

    let str = 'abaacdera';
    let reg = /a/;
    let arr2 = str.match(reg);
    console.log(arr2)      =>["a", index: 0, input: "abaacdera", groups: undefined]   看着像一个数组,其实不是。
    typeof(arr2)   =>    object
    
    let reg = /a/g;
    let arr3 = str.match(reg);
    console.log(arr3)    => ["a", "a", "a", "a"]  是一个数组
    
    let reg = /a+/g;
     let arr4 = str.match(reg);
    console.log(arr4)    => ["a", "aa", "a"]  是一个数组
    

    search:
    str.search(reg) 匹配成功返回对应得位置,不成功返回 -1

    let str = 'abaacdera';
    let reg = /aa/;
    let n= str.search(reg);
    console.log(n)    =>2
    

    replace:
    str.replace(reg,newstring) newstring需要替换成的东西 返回替换完成后的字符串

    let str = 'abaacdera';
    let reg = /a/;
    let str2 = str.replace(reg,'你好');
    console.log(str2)    =>'你好baacdera'
    
    let str = 'abaacdera';
    let reg = /a/g;
    let str2 = str.replace(reg,'你好');
    console.log(str2)     =>'你好b你好你好cder你好'
    
    let str = 'abaacdera';
    let reg = /az/g;
    let str2 = str.replace(reg,'你好');
    console.log(str2)     =>'abaacdera'
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  • 原文地址:https://www.cnblogs.com/xk-g/p/9155019.html
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