Summary of several usages of JavaScript to generate random numbers

 var chars = ['0','1','2','3','4','5','6','7','8','9','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']; function generateMixed(n) { var res = ""; for(var i = 0; i < n ; i ++) { var id = Math.ceil(Math.random()*35); res += chars[id]; } return res; }

Math.random()The result is a random number between 0-1 (including 0, excluding 1)

Math.floor(num)The parameter num is a numerical value, and the function result is the integer part of num.

Math.round(num)The parameter num is a numerical value, and the function result is the integer after num is rounded.

Math:Mathematical object, providing mathematical calculations on data.
Math.random();Returns a random number between 0 and 1 (including 0, excluding 1).

Math.ceil(n);Returns the smallest integer greater than or equal to n.
When using Math.ceil(Math.random()*10);, we mainly get random integers from 1 to 10, and the probability of getting 0 is very small.

Math.round(n);Returns the value of n after rounding.
UseMath.round(Math.random());to obtain a random integer from 0 to 1 evenly.
When usingMath.round(Math.random()*10);, random integers from 0 to 10 can be obtained in a basically balanced manner, and the probability of obtaining the minimum value 0 and the maximum value 10 is less than half.

Math.floor(n);Returns the largest integer less than or equal to n.
When usingMath.floor(Math.random()*10);, random integers from 0 to 9 can be obtained evenly.

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