javascript自動生成包含數字與字符的隨機字符串

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：

複製代碼代碼如下:/**

*

* 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AZ / az區間中隨機出現的字符

複製代碼代碼如下:/**

*

* 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：

複製代碼代碼如下: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。