How can I generate a radom number for twice?

Question

So guys I am trying to make a function that returns a random number (which I need that code to be executed excluesively) generate the same number for different two functions. Basically I am going to call a function that returns a random number but when I call that function again, I need it to be the same number as in the previous function (I am not very good at javascript.). I have these codes, but of course it generates some another number in each function:

function gen() {
    return Math.floor(Math.random() * 21) + 40;
}

function chan() {
    var rand = gen();
}

function sell() {
    var rand = gen();
}

Make `rand` a global variable and assign to it in `chan` and use it (without assigning to it) in `sell`. — ibrahim mahrir, Jul 22 '17 at 02:01

Eric Hoose · Answer 1 · 2017-07-22T02:12:42.883

3

You'll have to change your logic to get what you want it to do. It defeats the purpose of the rand function to try to force it to return the same value twice. Rather than that, just get the variable, and then pass it into the functions you need. Example:

function gen() {
  return Math.floor(Math.random() * 21) + 40;
}

function chan(randomNumber) {
 //logic goes here
}

function sell(randomNumber) {
  //logic goes here
}

function app() {
  var randomNumber = gen();
  chan(randomNumber);
  sell(randomNumber);
}

edited Jul 22 '17 at 02:12

answered Jul 22 '17 at 02:03

Eric Hoose

101
5

Thank you very much, for your immediate answer and help :) – Muhammed Ali Can Jul 22 '17 at 17:12

score 0 · Answer 2 · answered Jul 22 '17 at 02:08

var rand;
function gen() {
    return Math.floor(Math.random() * 21) + 40;
}

function chan() {
    rand = gen();
    return rand;
}

function sell() {
    return rand;
}

console.log(chan());
console.log(sell());

Basically create new random number everytime chan is called, and return that random number everytime sell is called.

score 0 · Answer 3 · answered Jul 22 '17 at 02:08

Basically I am going to call a function that returns a random number but when I call that function again, I need it to be the same number as in the previous function

You can store the current value of Math.floor(Math.random() * 21) + 40 as a property of the function if the property is not defined, return the property value, store the property value as a local variable within the function, else set the function property to undefined and return the local variable

function gen() {
  if (!this.n) {
    this.n = Math.floor(Math.random() * 21) + 40;
    return this.n;
  }
  if (this.n) {
    const curr = this.n;
    this.n = void 0;
    return curr
  }
}

for (let i = 0; i < 10; i++) {
  console.log(gen())
}

score -1 · Answer 4 · answered Jul 22 '17 at 02:03

-1

Just store the random number so that you can reuse it.

var rand;
function gen() {
return Math.floor(Math.random() * 21) + 40;
}

function chan() {
 rand = gen();
}

chan();
console.log(rand);

answered Jul 22 '17 at 02:03

Charlie Ng

640
5
11

why down vote? OP said he is not good at Javascript. Sometimes things can be simplified with another approach.. – Charlie Ng Jul 22 '17 at 02:08

How can I generate a radom number for twice?

4 Answers4