zheng 1 ngày trước cách đây
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commit
886df0798c

+ 27 - 0
正则/3.元字符-边界符.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <script>
+        // 1.\b 单词边界
+        var reg1 = /\ban\b/gi;
+        const str1 = 'An cat, is aAn animal';
+        console.log(str1.match(reg1));
+        // 2.^ 匹配字母首行
+        const reg2 = /^ab/;
+        console.log(reg2.test("ababab"));
+        // 3.$ 匹配字母尾行
+        const reg3 = /ab$/;
+        console.log(reg3.test("abababa"));
+
+        const reg4 = /^a$/;
+        console.log(reg4.test("aaa"));
+        console.log(reg4.test("a"));
+        console.log(reg4.test(" "));
+    </script>
+</body>
+</html>

+ 46 - 0
正则/4.元字符-量词.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <script>
+        // const reg = /a*$/;
+        // console.log(reg.test("aa"));
+        // console.log(reg.test(" "));
+        // console.log(reg.test("aab"));
+
+        // const reg = /a+$/;
+        // console.log(reg.test("aa"));
+        // console.log(reg.test(" "));
+        // console.log(reg.test("aab"));
+
+        // const reg = /a?a$/;
+        // console.log(reg.test("aa"));
+        // console.log(reg.test("a"));
+        // console.log(reg.test(" "));
+        // console.log(reg.test("aab"));
+
+        // const reg = /a{2}$/;
+        // console.log(reg.test("aa"));
+        // console.log(reg.test("a"));
+        // console.log(reg.test(" "));
+        // console.log(reg.test("aab"));
+
+        // const reg = /a{1,}$/;
+        // console.log(reg.test("aa"));
+        // console.log(reg.test("a"));
+        // console.log(reg.test(" "));
+        // console.log(reg.test("aab"));
+
+
+        const reg = /a{0,2}$/;
+        console.log(reg.test("aa"));
+        console.log(reg.test("a"));
+        console.log(reg.test(" "));
+        console.log(reg.test("aab"));
+    </script>
+</body>
+</html>

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正则/元字符.jpg


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正则/量词.jpg