Using loop to increment variable number in JavaScript

Question

I want to iterate multiple statements with "loop" I am wondering what I want to do is even possible with loop.

 var bomb = bombs.create(x,16,'bomb');
    bomb.setBounce(1);
    bomb.setCollideWorldBounds(true);
    bomb.setVelocity(Phaser.Math.Between(-200,200),20);
    bomb.allowGravity =false;

var bomb1 = bombs.create(x,16,'bomb');
    bomb1.setBounce(1);
    bomb1.setCollideWorldBounds(true);
    bomb1.setVelocity(Phaser.Math.Between(-200,200),20);
    bomb1.allowGravity =false;

var bomb2 = bombs.create(x,16,'bomb');
    bomb2.setBounce(1);
    bomb2.setCollideWorldBounds(true);
    bomb2.setVelocity(Phaser.Math.Between(-200,200),20);
    bomb2.allowGravity =false;

var bomb3 = bombs.create(x,16,'bomb');
    bomb3.setBounce(1);
    bomb3.setCollideWorldBounds(true);
    bomb3.setVelocity(Phaser.Math.Between(-200,200),20);
    bomb3.allowGravity =false;

The only change is the number incrementing right behind 'bomb' variable. Is it possible to use loop to iterate more than 100 times?

no, that's not possible, but you don't need that. What you need is an Array, here's a tutorial: https://developer.mozilla.org/en-US/docs/Learn/JavaScript/First_steps/Arrays — georg, May 04 '21 at 19:18

score 0 · Answer 1 · answered May 04 '21 at 19:29

Yes, you can use a loop this way, for example:

var objs = {}
const total = 10;

const getBomb = () => {
    var bomb = bombs.create(x, 16, 'bomb');
    bomb.setBounce(1);
    bomb.setCollideWorldBounds(true);
    bomb.setVelocity(Phaser.Math.Between(-200, 200), 20);
    bomb.allowGravity = false;

    return bomb;
}

for (let i = 0; i < total; i++) {
    objs[`bomb${i}`] = getBomb();
}

console.log('objs', objs)

score 0 · Answer 2 · answered May 04 '21 at 19:33

let bombArray = Array(100).fill().map(_=> {
    let bomb = bombs.create(x, 16, 'bomb');
    bomb.setBounce(1);
    bomb.setCollideWorldBounds(true);
    bomb.setVelocity(Phaser.Math.Between(-200, 200), 20);
    bomb.allowGravity = false;
    return bomb;
});

Erfan Bahramali · Answer 3 · 2021-05-04T19:39:01.087

I do not think it is very appropriate to use the names of dynamic variables in JavaScript

In these cases, you can use arrays

Example:

var allBombs = [];
for (let i = 0; i < 100; i++) {
    var bomb = bombs.create(x, 16, 'bomb');
    bomb.setBounce(1);
    bomb.setCollideWorldBounds(true);
    bomb.setVelocity(Phaser.Math.Between(-200, 200), 20);
    bomb.allowGravity = false;
    allBombs.push(bomb);
}
console.log(allBombs);// log all
console.log(allBombs['15']);// log one(15)

But again, there are solutions for that, which I suggest you follow the following:

Example:

var k = 'bomb';
var i = 0;
for(i = 1; i < 5; i++) {
    eval('var ' + k + i + '= ' + i + ';');
}
console.log("bomb1=" + bomb1);
console.log("bomb2=" + bomb2);
console.log("bomb3=" + bomb3);
console.log("bomb4=" + bomb4);

Contents:

How do I create dynamic variable names inside a loop?

Use dynamic variable names in JavaScript

https://www.geeksforgeeks.org/how-to-use-dynamic-variable-names-in-javascript/

https://www.sitepoint.com/community/t/dynamic-i-variable-names-in-javascript/4236/2

If you find other questions that have the answer, please flag the question as a duplicate, don't answer. — Heretic Monkey, May 04 '21 at 19:38
True, but I think this question could be a little different from other questions , Because I do not think the method is important and is looking for a solution, I also said 2 different solutions — Erfan Bahramali, May 04 '21 at 19:47

score 0 · Accepted Answer · answered May 04 '21 at 19:37

// Bomb constructor for demo - you would use `bombs.create` function here
function Bomb() {
  this.collideWorldBounds = true;
  this.velocity = null;
  this.allowGravity = false;
}

// An array to store all bombs, use this instead of bomb1, bomb2, bomb3 etc.
const bombs = [];

// Loop a predetermined number of iterations and populate the array.
for (let i = 0; i < 100; i++) {
  const bomb = new Bomb();
  // Set any additional `bomb` instance properties here
  bombs.push(bomb);
}

// See contents of the array
console.log(bombs);

Using loop to increment variable number in JavaScript

4 Answers4