javascript随机生成字符串

//第一种

function randPassword()

{

var text=['abcdefghijklmnopqrstuvwxyz','ABCDEFGHIJKLMNOPQRSTUVWXYZ','1234567890','z'];

var rand = function(min, max){return Math.floor(Math.max(min, Math.random() * (max+1)));}

var len = rand(4, 8); // 长度为8-16

var pw = '';

for(i=0; i<len; ++i)

{

var strpos = rand(0, 3);

pw += text[strpos].charAt(rand(0, text[strpos].length));

}

return pw;

}

var a = randPassword();

alert(a);

//第二种

function randomString(length) {

var chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz'.split('');



if (! length) {

length = Math.floor(Math.random() * chars.length);

}



var str = '';

for (var i = 0; i < length; i++) {

str += chars[Math.floor(Math.random() * chars.length)];

}

return 'buyuy_'+str;

}

/* examples */

// generate a random string of random length

//randomString();

// generate a random string of length 8

var a =randomString(4);