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  • JS生成uuid的四种方法

      在开发过程中,有时候需要js生成全局唯一标识符,在java中可以使用uuid,但是JS中没有现成的函数。总结了一下,JS生成唯一标识符的几种方法。

    第一种:

    function guid() {
        return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
            var r = Math.random() * 16 | 0,
                v = c == 'x' ? r : (r & 0x3 | 0x8);
            return v.toString(16);
        });
    }
    guid() // "a1ca0f7b-51bd-4bf3-a5d5-6a74f6adc1c7"

    第二种:

    function uuid() {
        var s = [];
        var hexDigits = "0123456789abcdef";
        for (var i = 0; i < 36; i++) {
            s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
        }
        s[14] = "4"; // bits 12-15 of the time_hi_and_version field to 0010
        s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1); // bits 6-7 of the clock_seq_hi_and_reserved to 01
        s[8] = s[13] = s[18] = s[23] = "-";
    
        var uuid = s.join("");
        return uuid;
    }
    uuid() // "ffb7cefd-02cb-4853-8238-c0292cf988d5"

    第三种:

    function guid2() {
        function S4() {
            return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
        }
        return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
    }
    guid2() // "748eea29-f842-4af9-a552-e1e1aa3ed979"

    第四种:

    // 指定长度和基数
    function uuid2(len, radix) {
        var chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
        var uuid = [],
            i;
        radix = radix || chars.length;
    
        if (len) {
            // Compact form
            for (i = 0; i < len; i++) uuid[i] = chars[0 | Math.random() * radix];
        } else {
            // rfc4122, version 4 form
            var r;
    
            // rfc4122 requires these characters
            uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
            uuid[14] = '4';
    
            // Fill in random data.  At i==19 set the high bits of clock sequence as
            // per rfc4122, sec. 4.1.5
            for (i = 0; i < 36; i++) {
                if (!uuid[i]) {
                    r = 0 | Math.random() * 16;
                    uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
                }
            }
        }
    
        return uuid.join('');
    }
    uuid2(16, 16) // "277571702EE33E11"
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  • 原文地址:https://www.cnblogs.com/goloving/p/13853524.html
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