javascript - 正则表达式模式测试在 JavaScript 中失败

Question

我有下面的正则表达式来验证字符串..

var str = "Thebestthingsinlifearefree";
var patt = /[^0-9A-Za-z !\\#$%&()*+,\-.\/:;<=>?@\[\]^_`{|}~]*/g;
var res = patt.test(str);

结果总是给出 true，但我认为它会给出 false.. 因为我检查了 patt 变量中没有的任何模式...

给定的字符串有效，并且仅包含大写和小写字母。不确定该模式有什么问题。

Answer 1

这是您的代码:

var str = "Thebestthingsinlifearefree";
var patt = /[^0-9A-Za-z !\\#$%&()*+,\-.\/:;<=>?@\[\]^_`{|}~]*/g;
console.log(patt.test(str));

正则表达式

/[^0-9A-Za-z !\\#$%&()*+,\-.\/:;<=>?@\[\]^_`{|}~]*/g

将匹配任何内容，因为由于量词*，它接受长度为0的匹配。

只需添加 anchor :

var str = "Thebestthingsinlifearefree";
var patt = /^[^0-9A-Za-z !\\#$%&()*+,\-.\/:;<=>?@\[\]^_`{|}~]*$/;
console.log(patt.test(str));

<小时/>

这是您的正则表达式的解释:

[^0-9A-Za-z !\\#$%&()*+,\-.\/:;<=>?@\[\]^_`{|}~]* match a single character not present in the list below

    Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
    0-9 a single character in the range between 0 and 9
    A-Z a single character in the range between A and Z (case sensitive)
    a-z a single character in the range between a and z (case sensitive)
     ! a single character in the list  ! literally
    \\ matches the character \ literally
    #$%&()*+, a single character in the list #$%&()*+, literally (case sensitive)
    \- matches the character - literally
    . the literal character .
    \/ matches the character / literally
    :;<=>?@ a single character in the list :;<=>?@ literally (case sensitive)
    \[ matches the character [ literally
    \] matches the character ] literally
    ^_`{|}~ a single character in the list ^_`{|}~ literally