匹配正则使用.test方法匹配多个模式使用操作符号

正则表达式或“regex”用于匹配字符串的各个部分，下面是作者创建正则表达式的备忘单js正则匹配多个字符串，供大家学习参考。

匹配正则

使用.test()方法

<pre class="code-snippet__js" data-lang="javascript">let testString = "My test string";`let testRegex = /string/;`testRegex.test(testString);</pre>

匹配多个模式

使用操作符号|

<pre class="code-snippet__js" data-lang="javascript">const regex = /yes|no|maybe/; </pre>

忽略大小写

使用i标志表示忽略大小写

<pre class="code-snippet__js" data-lang="javascript">const caseInsensitiveRegex = /ignore case/i;`const testString = 'We use the i flag to iGnOrE CasE';`caseInsensitiveRegex.test(testString); // true</pre>

提取变量的第一个匹配项

使用.match()方法

c#正则表达式匹配任意字符_js正则匹配多个字符串_正则表达式匹配任意字符

<pre class="code-snippet__js" data-lang="javascript">const match = "Hello World!".match(/hello/i); // "Hello"</pre>

提取数组中的所有匹配项

使用g标志

<pre class="code-snippet__js" data-lang="ruby">const testString = "Repeat repeat rePeAT";`const regexWithAllMatches = /Repeat/gi;`testString.match(regexWithAllMatches); // ["Repeat", "repeat", "rePeAT"] </pre>

匹配任意字符

使用通配符.作为任何字符的占位符

<pre class="code-snippet__js" data-lang="bash">// To match "cat", "BAT", "fAT", "mat"`const regexWithWildcard = /.at/gi;const testString = "cat BAT cupcake fAT mat dog";const allMatchingWords = testString.match(regexWithWildcard); // ["cat", "BAT", "fAT", "mat"] `用多种可能性匹配单个字符</pre>

<pre class="code-snippet__js" data-lang="perl">//匹配 "cat" "fat" and "mat" 但不匹配 "bat"`const regexWithCharClass = /[cfm]at/g;const testString = "cat fat bat mat";const allMatchingWords = testString.match(regexWithCharClass); // ["cat", "fat", "mat"] `</pre>

匹配字母表中的字母

使用字符集内的范围[a-z]

<pre class="code-snippet__js" data-lang="javascript">const regexWidthCharRange = /[a-e]at/;` const regexWithCharRange = /[a-e]at/;const catString = "cat";const batString = "bat";const fatString = "fat"; regexWithCharRange.test(catString); // trueregexWithCharRange.test(batString); // trueregexWithCharRange.test(fatString); // false`</pre>

匹配特定的数字和字母

你还可以使用连字符来匹配数字

<pre class="code-snippet__js" data-lang="javascript">const regexWithLetterAndNumberRange = /[a-z0-9]/ig;`const testString = "Emma19382";`testString.match(regexWithLetterAndNumberRange) // true</pre>

匹配单个未知字符

要匹配您不想拥有的一组字符，使用否定字符集^

<pre class="code-snippet__js" data-lang="javascript">const allCharsNotVowels = /[^aeiou]/gi;`const allCharsNotVowelsOrNumbers = /¹/gi;`</pre>

匹配一行中出现一次或多次的字符

使用+标志

<pre class="code-snippet__js" data-lang="javascript">const oneOrMoreAsRegex = /a+/gi;`const oneOrMoreSsRegex = /s+/gi;const cityInFlorida = "Tallahassee"; cityInFlorida.match(oneOrMoreAsRegex); // ['a', 'a', 'a'];cityInFlorida.match(oneOrMoreSsRegex); // ['ss']; `</pre>

匹配连续出现零次或多次的字符

使用星号*

<pre class="code-snippet__js" data-lang="javascript">const zeroOrMoreOsRegex = /hi*/gi;`const normalHi = "hi";const happyHi = "hiiiiii";const twoHis = "hiihii";const bye = "bye"; normalHi.match(zeroOrMoreOsRegex); // ["hi"]happyHi.match(zeroOrMoreOsRegex); // ["hiiiiii"]twoHis.match(zeroOrMoreOsRegex); // ["hii", "hii"]bye.match(zeroOrMoreOsRegex); // null` </pre>

惰性匹配

正则表达式匹配任意字符_js正则匹配多个字符串_c#正则表达式匹配任意字符

<pre class="code-snippet__js" data-lang="javascript"> const testString = "catastrophe";` const greedyRexex = /c[a-z]*t/gi; const lazyRegex = /c[a-z]*?t/gi; testString.match(greedyRexex); // ["catast"] testString.match(lazyRegex); // ["cat"] `</pre>

匹配起始字符串模式

要测试字符串开头的字符匹配，请使用插入符号^，但要放大开头，不要放到字符集中

<pre class="code-snippet__js" data-lang="javascript">const emmaAtFrontOfString = "Emma likes cats a lot.";`const emmaNotAtFrontOfString = "The cats Emma likes are fluffy.";const startingStringRegex = /^Emma/; startingStringRegex.test(emmaAtFrontOfString); // truestartingStringRegex.test(emmaNotAtFrontOfString); // false ` </pre>

匹配结束字符串模式

使用$来判断字符串是否是以规定的字符结尾

<pre class="code-snippet__js" data-lang="javascript">const emmaAtBackOfString = "The cats do not like Emma";`const emmaNotAtBackOfString = "Emma loves the cats";const startingStringRegex = /Emma$/; startingStringRegex.test(emmaAtBackOfString); // truestartingStringRegex.test(emmaNotAtBackOfString); // false `</pre>

匹配所有字母和数字

使用word简写

<pre class="code-snippet__js" data-lang="javascript">const longHand = /[A-Za-z0-9_]+/;`const shortHand = /w+/;const numbers = "42";const myFavoriteColor = "magenta"; longHand.test(numbers); // trueshortHand.test(numbers); // truelongHand.test(myFavoriteColor); // true`shortHand.test(myFavoriteColor); // true</pre>

除了字母和数字，其他的都要匹配

用W表示w的反义

<pre class="code-snippet__js" data-lang="javascript">const noAlphaNumericCharRegex = /\W/gi;`const weirdCharacters = "!_$!!";const alphaNumericCharacters = "ab283AD"; noAlphaNumericCharRegex.test(weirdCharacters); // truenoAlphaNumericCharRegex.test(alphaNumericCharacters); // false` </pre>

匹配所有数字

你可以使用字符集[0-9]js正则匹配多个字符串，或者使用简写d

<pre class="code-snippet__js" data-lang="ruby">const digitsRegex = /\d/g;`const stringWithDigits = "My cat eats $20.00 worth of food a week."; stringWithDigits.match(digitsRegex); // ["2", "0", "0", "0"]` </pre>

匹配所有非数字

用D表示d的反义

<pre class="code-snippet__js" data-lang="ruby">const nonDigitsRegex = /\D/g;`const stringWithLetters = "101 degrees"; stringWithLetters.match(nonDigitsRegex); // [" ", "d", "e", "g", "r", "e", "e", "s"]`</pre>

匹配空格

使用s来匹配空格和回车符

<pre class="code-snippet__js" data-lang="javascript">const sentenceWithWhitespace = "I like cats!"`var spaceRegex = /s/g;`whiteSpace.match(sentenceWithWhitespace); // [" ", " "]</pre>

匹配非空格

用S表示s的反义

<pre class="code-snippet__js" data-lang="javascript">const sentenceWithWhitespace = "C a t"`const nonWhiteSpaceRegex = /S/g;sentenceWithWhitespace.match(nonWhiteSpaceRegex); // ["C", "a", "t"] `</pre>

匹配的字符数

你可以使用{下界，上界}指定一行中的特定字符数

<pre class="code-snippet__js" data-lang="javascript">const regularHi = "hi";`const mediocreHi = "hiii";const superExcitedHey = "heeeeyyyyy!!!";const excitedRegex = /hi{1,4}/; excitedRegex.test(regularHi); // trueexcitedRegex.test(mediocreHi); // trueexcitedRegex.test(superExcitedHey); //false`</pre>

匹配最低个数的字符数

使用{下界, }定义最少数量的字符要求,下面示例表示字母i至少要出现2次

<pre class="code-snippet__js" data-lang="javascript">const regularHi = "hi";`const mediocreHi = "hiii";const superExcitedHey = "heeeeyyyyy!!!";const excitedRegex = /hi{2,}/; excitedRegex.test(regularHi); // falseexcitedRegex.test(mediocreHi); // trueexcitedRegex.test(superExcitedHey); //false`</pre>

匹配精确的字符数

使用{requiredCount}指定字符要求的确切数量

<pre class="code-snippet__js" data-lang="javascript">const regularHi = "hi";`const bestHi = "hii";const mediocreHi = "hiii";const excitedRegex = /hi{2}/; excitedRegex.test(regularHi); // falseexcitedRegex.test(bestHi); // trueexcitedRegex.test(mediocreHi); //false `</pre>

匹配0次或1次

使用?匹配字符 0 次或1次

<pre class="code-snippet__js" data-lang="javascript">const britishSpelling = "colour";`const americanSpelling = "Color";const languageRegex = /colou?r/i; languageRegex.test(britishSpelling); // truelanguageRegex.test(americanSpelling); // true`</pre>