Javascript - 从一组指定值生成指定长度的随机数

Question

我想从一组指定的字符中生成一个长度为 32 个字符的随机数。

例如:

var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZ";
var string_length = 32;

然后将使用指定的字符返回长度为 32 的随机数。

Answer 1

是这样的吗？

查看 jsfiddle。我对其进行了修改，以便您可以看到结果增长时的进展:http://jsfiddle.net/YuyNL/

var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZ";   // Pool of potential characters
var string_length = 32;                     // Desired length of result
var num_chars = chars.length;               // Total number of characters in pool
var result = '';                      // Container to store result

while(string_length--) {      // Run a loop for a duration equal to the length of the result

  // For each iteration, get a random number from 0 to the size of the
  //   number of characters you're using, use that number to grab the index
  //   of the character stored in 'chars', and add it to the end of the result

    result += chars[ Math.floor( Math.random() * num_chars ) ];  

}

$('body').append(result + '<br>');  // This just appends the result to the 'body'
                                    //    if you're using jQuery