JSFiddle - React, Tailwind, and code Playground

by tobyworth

JavaScript

function forEach(arr, action){
	for(let i=0; i<arr.length; i++){
  	action(arr[i]);
  }
}

function reduce(func, base, arr){	
	forEach(arr, function(elm){
  		base += func(elm) ? 1 : 0;
  });
  
  return base;
}

let isDoubleMultiple = (x, y) => {
	return function(element){
  	if(element===0) return false; 
  	return element % x === 0 && element % y === 0;
  }
}

let isTripleMultiple = (x, y, z) => {
	return function(element){
  	if(element===0) return false;
  	return element % x === 0 && element % y === 0 && element % z === 0;
  }
}

function count(func, arr){
	return reduce(func, 0, arr);
}

function countZeroes(arr){
	return count(isZero(), arr);
}

alert(count(isDoubleMultiple(2,4), [0,1,2,3,0,4]));	// 1
alert(count(isDoubleMultiple(3,9), [1,2,0,3,4,9,27]));	// 2
alert(count(isTripleMultiple(3,9,27), [1,2,3,0,4,9,27,54,81,99,101,108]));	// 3