javascript - 在JavaScript中生成随机字符串/字符(Generate random string/characters in JavaScript)

Question

I want a 5 character string composed of characters picked randomly from the set [a-zA-Z0-9] .

(我想要一个由从[a-zA-Z0-9]随机挑选的字符组成的5个字符串。)

What's the best way to do this with JavaScript?

(用JavaScript做到这一点的最佳方法是什么？)

  ask by Tom Lehman translate from so

Answer 1

 let r = Math.random().toString(36).substring(7); console.log("random", r); 

Note: The above algorithm has the following weaknesses:

(注意：以上算法具有以下缺点：)

• It will generate anywhere between 0 and 6 characters due to the fact that trailing zeros get removed when stringifying floating points.

  (由于在对浮点进行字符串化时会删除尾随零，因此它将生成0到6个字符之间的任意位置。)

• It depends deeply on the algorithm used to stringify floating point numbers, which is horrifically complex.

  (这在很大程度上取决于用于对浮点数进行字符串化的算法，该算法极其复杂。)

  (See the paper "How to Print Floating-Point Numbers Accurately" .)

  (（请参阅论文“如何准确打印浮点数” 。）)

• Math.random() may produce predictable ("random-looking" but not really random) output depending on the implementation.

  (Math.random()可能会产生可预测的（“看起来很随机”，但不是真正随机的）输出。)

  The resulting string is not suitable when you need to guarantee uniqueness or unpredictability.

  (当您需要保证唯一性或不可预测性时，结果字符串不适合。)

• Even if it produced 6 uniformly random, unpredictable characters, you can expect to see a duplicate after generating only about 50,000 strings, due to the birthday paradox .

  (即使它产生了6个均匀随机且不可预测的字符，由于生日悖论 ，您也可以期望仅生成大约50,000个字符串后看到重复项。)

  (sqrt(36^6) = 46656)

  (（sqrt（36 ^ 6）= 46656）)