A summary of methods for generating random numbers by JS

JS generates random numbers primarily using the random () method of the built-in math object. Usage such as: Math.random (). It returns a random number between 0 and 1. With such a method, it is understandable to generate arbitrary random numbers. For example, in practice we may have the following needs:

(1) generate a random integer between 0-100, then you can:

Note: Because the return value of Math.random () is 0 and 1, there is the possibility of generating 0 and 100.

(2) generate a random integer from M-n, for example to generate a random number between 5-15, you can:

1

The summary is:

parseint (Math.random () * (n-m+1) +m);//Generate a random integer from M-n

In addition, according to the need www.phpernote.com summed up the other two commonly used methods, as follows:

(1) generating a random integer of the specified number of digits

1      function  2        var t= '3for        (var i=0;i<n;i++  4          T+=math.floor (math.random () *105       6        return  t; 7

(2) Generate random integers in the specified range

1 functionRandomnum (minnum,maxnum) {2     Switch(arguments.length) {3          Case1: 4             returnparseint (Math.random () *minnum+1); 5          Break; 6          Case2: 7             returnparseint (Math.random () * (maxnum-minnum+1) +minnum); 8          Break; 9         default: Ten             return0;  One          Break;  A     }  -}

For example, to generate a random integer between 2-9, then: Randomnum (2,9), generates a random integer between 1-22, then: Randomnum (22)

A summary of methods for generating random numbers by JS