Return true when all elements in array are false (p5js)?

gabotonatiu

Hi. I'm trying to recreate the classic breakout game. To go to the next level I need to have a variable that changes to true when all element on array are false (when all the boxes have been destroyed). This is what I think should work, but it returns true as soon as one element becomes false.

var allTrue = false;

for (var r = 0; r < rows; r++) {
    for (var c = 0; c < col; c++) {
      if(boxes[r][c] == false){
             allTrue = true;
                 } 
        }
}

kfrajer

Check this below. If only one box is false, allTrue becomes false.

Kf

var allTrue = true;

for (var r = 0; r < rows; r++) {
    for (var c = 0; c < col; c++) {
            allTrue   &= ! ( boxes[r][c] );     
        }
}

GoToLoop

1. https://developer.Mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/some
2. https://developer.Mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/fill
3. https://developer.Mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of

  
// https://forum.Processing.org/two/discussion/22930/
// return-true-when-all-elements-in-array-are-false-p5js#Item_2

// GoToLoop (2017-Jun-05)

"use strict";

const ROWS = 3, COLS = 9,
      IS_TRUE = bool => bool,
      boxes = Array(ROWS);

function createBoxes2dArray() {
  for (let i = 0; i < ROWS; boxes[i++] = new Int8Array(COLS));
}

function resetAllBoxes() {
  for (const row of boxes)  row.fill(true);
}

function areAllBoxesDestroyed() {
  for (const row of boxes)  if (row.some(IS_TRUE))  return false;
  return true;
}

createBoxes2dArray(); // 2d array boxes is created, but not initialized yet
console.log(areAllBoxesDestroyed()); // true b/c all is still false

resetAllBoxes(); // fill 2d array boxes w/ value true
console.log(areAllBoxesDestroyed()); // false b/c all or some is now true

P.S.: The sample above can be copied & pasted & run directly at any modern browser's console. \m/

GoToLoop

A slightly variant version, mixing up some() & every() methods inside areAllBoxesDestroyed(): :bz

https://developer.Mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every

// https://forum.Processing.org/two/discussion/22930/
// return-true-when-all-elements-in-array-are-false-p5js#Item_3

// GoToLoop (2017-Jun-05)

"use strict";

const ROWS = 3, COLS = 9,
      IS_TRUE = bool => bool,
      ROW_FALSE = row => !row.some(IS_TRUE),
      boxes = Array(ROWS);

function createBoxes2dArray() {
  for (let i = 0; i < ROWS; boxes[i++] = new Int8Array(COLS));
}

function resetAllBoxes() {
  for (const row of boxes)  row.fill(true);
}

function areAllBoxesDestroyed() {
  return boxes.every(ROW_FALSE);
}

createBoxes2dArray(); // 2d array boxes is created, but not initialized yet
console.log(areAllBoxesDestroyed()); // true b/c all is still false

resetAllBoxes(); // fill 2d array boxes w/ value true
console.log(areAllBoxesDestroyed()); // false b/c all or some is now true

Again, we can open browser's console by hitting F12 and paste the sample above at console's tab: :ar!

kristianp89

Is this what you're looking for?

[false, true, false].every(element => element === false) // false

[false, false, false].every(element => element === false) // true

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every