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javascript自動生成包含數字與字符的隨機字符串
編輯:關於JavaScript     

本文實例講述了javascript自動生成包含數字與字符的隨機字符串的方法。分享給大家供大家參考。具體如下:

這裡主要用到Math.random() 和 Math.floor() 兩個函數

Math.random()   -- 返回0和1之間的偽隨機數 可能為0,但總是小於1,[0,1)

Math.floor()    -- 向下取整,捨掉小數字後的值

實現隨機多位數的方法:

代碼如下:/**
*
*    隨機生成數字
*
*@param num 生成數字位數
*/ 
function randomNumber(num){ 
        return ''+Math.floor(Math.random() * num) ; 
}

javascript 隨機生成字符

以下實例為隨機 A-Z / a-z區間 中隨機出現的字符
代碼如下:/**
 *
 *    隨機生成
 *
 *@param data json數據 例:{"start":0,"end":2,"number":5,"upper":true} 
 *@param start  開始下標
 *@param end    結束下標
 *@param number 生成位數
 *@param upper  是否大寫 默認為小寫
 */ 
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:
代碼如下:alert(new Date().Format("yyyy-MM-dd hh:mm:ss"));

希望本文所述對大家的javascript程序設計有所幫助。

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