json--code

///
//

<!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>
        /* 
            正则表达式中的修饰符
            i:忽略大小写
            g:全局匹配
            ig:既忽略大小写,也全局匹配
        
        */

        // var reg = /a/i;
        // console.log(reg.test('Abc'))


        var reg = /a/g;
        console.log('abcaAbc'.match(reg))


        var reg = /a/gi;
        console.log('abcaAbc'.match(reg))
    </script>
</body>
</html>

//
//

<!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>
        /* 
            exec方法
            1.作用:该方法时正则表达式对象的一个方法,可以利用这个方法在字符串中检索是否有和该正则表达式匹配的子串,如果有,则返回,有点类似于match方法
            2.格式:正则表达式.exec(字符串);
        */

        var str = 'abcabcabc';
        var reg = /a/g;

        var res = reg.exec(str);
        console.log(res);

        var res = reg.exec(str);
        console.log(res);

        var res = reg.exec(str);
        console.log(res);

        var res = reg.exec(str);
        console.log(res);

        var res = reg.exec(str);
        console.log(res);

        var res = reg.exec(str);
        console.log(res);
    </script>
</body>
</html>

//
//
//

<!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>
        // 利用indexOf方法对下面的数组进行去重

        var arr = [1, 2, 1, 3, 2, 3, 3, 4, 4, 5, 1];
        var newArr = [];

        for (var i=0; i<arr.length; i++) {
            if (newArr.indexOf(arr[i]) == -1) {
                newArr.push(arr[i]);
            }
        }

        console.log(newArr);
    </script>
</body>
</html>

//
//
//

<!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>
        // 利用splice方法对数组进行去重
        var arr = [1, 2, 1, 3, 2, 3, 3, 4, 4, 5, 1];

        for (var i=0; i<arr.length; i++) {//当前元素为3----下标为3
            for (var j=i+1; j<arr.length; j++) {//5
                if (arr[i] == arr[j]) {
                    arr.splice(j, 1);
                    j--;
                }
            }
        }

        console.log(arr);
    </script>
</body>
</html>

//
//


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