Summary of methods for generating random numbers in JS

The code is as follows:

<script>  
function GetRandomNum(Min,Max)
{  
var Range = Max - Min;  
var Rand = Math.random();  
return(Min + Math.round(Rand * Range));  
}  
var num = GetRandomNum(1,10);  
alert(num);  
</script>
var chars = [&#39;0&#39;,&#39;1&#39;,&#39;2&#39;,&#39;3&#39;,&#39;4&#39;,&#39;5&#39;,&#39;6&#39;,&#39;7&#39;,&#39;8&#39;,&#39;9&#39;,&#39;A&#39;,&#39;B&#39;,&#39;C&#39;,&#39;D&#39;,&#39;E&#39;,&#39;F&#39;,&#39;G&#39;,&#39;H&#39;,&#39;I&#39;,&#39;J&#39;,&#39;K&#39;,&#39;L&#39;,&#39;M&#39;,&#39;N&#39;,&#39;O&#39;,&#39;P&#39;,&#39;Q&#39;,&#39;R&#39;,&#39;S&#39;,&#39;T&#39;,&#39;U&#39;,&#39;V&#39;,&#39;W&#39;,&#39;X&#39;,&#39;Y&#39;,&#39;Z&#39;];
function generateMixed(n) {
   var res = "";
   for(var i = 0; i < n ; i ++) {
     var id = Math.ceil(Math.random()*35);
     res += chars[id];
   }
   return res;
}

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

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

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

Math: MathObject, provides 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);, you 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.

Use Math.round(Math.random()); to obtain a balanced random integer from 0 to 1.

When using Math.round(Math.random()*10);, you can basically obtain random integers from 0 to 10 in a 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 using Math.floor(Math.random()*10);, random integers from 0 to 9 can be obtained evenly.

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