javascript自动生成包含数字与字符的随机字符串

本文实例讲述了javascript自动生成包含数字与字符的随机字符串的方法。分享给大家供大家参考。具体如下:

这里主要用到Math.random() 和 Math.floor() 两个函数

Math.random()   -- 返回0和1之间的伪随机数 可能为0,但总是小于1,[0,1)

Math.floor()    -- 向下取整,舍掉小数字后的值

实现随机多位数的方法:

/** 

*

*    随机生成数字

*

*@param num 生成数字位数

*/ 

function randomNumber(num){ 

        return ''+Math.floor(Math.random() * num) ; 

}

javascript 随机生成字符

以下实例为随机 A-Z / a-z区间 中随机出现的字符

/** 

 *

 *    随机生成

 *

 *@param data json数据 例:{"start":0,"end":2,"number":5,"upper":true} 

 *@param start  开始下标

 *@param end    结束下标

 *@param number 生成位数

 *@param upper  是否大写 默认为小写

 */ 

function randomLetter(data){ 

    var letterData = ""; 

    var lowercase = new Array("a","b","c","d","e","f","g","h","i","g","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"); 

 

    var uppercase = new Array("A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"); 

    var start = data.start; 

    var end = data.end; 

    var number = data.number; 

    var upper = data.upper; 

 

    var length = end - start; 

    for(var i= 0;i < number; i++){ 

        var index = Math.floor(Math.random() * length) + start; 

        var letter = ""; 

        if(upper){ 

            letter = uppercase[index]; 

        }else{ 

            letter = lowercase[index]; 

        } 

        letterData += letter; 

    } 

    return letterData;  

}

引用:

alert(new Date().Format("yyyy-MM-dd hh:mm:ss"));

希望本文所述对大家的javascript程序设计有所帮助。

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