Foreword:
JS does not have a ready-made function that can directly generate random numbers in a specified range.
But it has a function: Math.random() This function can generate a random number in [0,1).
Using it, we can generate random numbers within a specified range.
When it comes to range, there is a problem of boundary values. This includes four situations:
1) min ≤ r ≤ max (generally this is more common)
2) min ≤ r < max
3) min < r ≤ max
4) min < r < max
1. min ≤ r ≤ max
function RandomNumBoth(Min,Max){
var Range = Max - Min;
var Rand = Math.random();
var num = Min + Math.round(Rand * Range); //四舍五入
return num;
}2. min ≤ r < max
function RandomNum(Min, Max) {
var Range = Max - Min;
var Rand = Math.random();
var num = Min + Math.floor(Rand * Range); //舍去
return num;
}3. min < r ≤ max
function RandomNum(Min, Max) {
var Range = Max - Min;
var Rand = Math.random();
if(Math.round(Rand * Range)==0){
return Min + 1;
}
var num = Min + Math.round(Rand * Range);
return num;
}4. min < r < max
function RandomNum(Min, Max) {
var Range = Max - Min;
var Rand = Math.random();
if(Math.round(Rand * Range)==0){
return Min + 1;
}else if(Math.round(Rand * Max)==Max)
{
index++;
return Max - 1;
}else{
var num = Min + Math.round(Rand * Range) - 1;
return num;
}
}The above article about JS generating random numbers in a certain range [detailed explanation of four situations] is all the content shared by the editor. I hope it can give you a reference, and I hope you will support Script Home more.
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