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Posted: **25 Oct 2020, 12:26**

I have 3 arrays of objects in JavaScript:

const fruits = [
{name: "Banana"}, 
{name: "Apple"}, 
{name: "Peach"}
]

const car = [
{name: "Audi"}, 
{name: "Bentley"}
]

const books = [
{name: "Alice in wonderland"}, 
{name: "Deep in the dark"}, 
{name: "Hunting Show"}
]

One temporary array where I will store random objects from arrays:

Code: Select all

const tempArray = []

I want to get random object from random array.

50% percentage chance that I get random object from fruits.
30% percentage chance that I get random object from car array.
20% percentage chance that I get random object from books array.

Example:
- Random chance is 50% -> random object from array fruits is pushed to tempArray and tempArray should have object with bane "Banana".
- Random chance is 20% -> Random object from array books is pushed to tempArray and tempArray should have object with name "Hunting Show".

How can I do it in javascript?

Posted: **25 Oct 2020, 12:38**

You need to get two random numbers:
- the first to decide which group to pick,
- the second to pick an item from that.

We generate a random number from 1 to 100.
- A number from 1 to 20 would pick a random element from the books array,
- a number from 21 to 50 would pick a random element from the car array,
- a number from 51 to 100 would pick a random element from the fruits array.

Code: Select all

const fruits = [
  {name: "Banana"}, 
  {name: "Apple"}, 
  {name: "Peach"}
]

const car = [
  {name: "Audi"}, 
  {name: "Bentley"}
]

const books = [
  {name: "Alice in wonderland"}, 
  {name: "Deep in the dark"}, 
  {name: "Hunting Show"}
]

const tempArray = []

let randomNumber = Math.floor((Math.random() * 100) + 1); // 1 to 100

if (randomNumber < 21) {
  let randomIndex = Math.floor(Math.random() * books.length); // 0 to 3
  tempArray.push(books[randomIndex]);
}
else if (randomNumber < 51) {
  let randomIndex = Math.floor(Math.random() * car.length); // 0 or 1
  tempArray.push(car[randomIndex]);
}
else {
  let randomIndex = Math.floor(Math.random() * fruits.length); // 0 to 2
  tempArray.push(fruits[randomIndex]);
}

console.log('tempArray: ' + JSON.stringify(tempArray));

Forum

Random object from multiple arrays with percent chance in JS

Random object from multiple arrays with percent chance in JS

Random object from multiple arrays with percent chance in JS