js/array_iteration.js at master · prabhu-sundaram/js · GitHub

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const fruits3 = ["Banana", "Orange", "Apple", "Mango"];
let fLen = fruits3.length;
for (let i = 0; i < fLen; i++) {
  console.log(fruits3[i]);
}

var text = "";
function myFunction2(value) {
  text += value+",";
}
fruits3.forEach(myFunction2);
console.log(text);

console.log("=========================");

console.log('-----map--------');
var numbers1 = [45, 4, 9, 16, 25];
var numbers2 = numbers1.map(myFunction);

function myFunction(value, index, array) {
  return value * 2;
}
var numbers3 = numbers2.map(myFun);

function myFun(value) {
    return value * 2;
  }
console.log(numbers1);
console.log(numbers2);
console.log(numbers3);
console.log("=========================");

console.log('-----filter--------');
var numbers4 = [45, 4, 9, 16, 25];
var over18 = numbers4.filter(myFunction4);

function myFunction4(value) {
  return value > 18;
}
console.log(numbers4);
console.log(over18);
console.log("=========================");

console.log('-----reduce--------');
var numbers5 = [45, 4, 9, 16, 25];
console.log(numbers5);


function myFunction5(total, value, index, array) {
  return total + value;
}
var sum = numbers5.reduce(myFunction5);
console.log(sum);
console.log("=========================");

console.log('-----reduce--------initial value-------------');

var numbers6 = [45, 4, 9, 16, 25];
var sum2 = numbers6.reduce(myFunction6, 100);//initial value 100

function myFunction6(total, value) {
  console.log(value,total);
  return total + value;
}

console.log(sum2);
console.log("=========================");

console.log('-----reduceRight--------');

var numbers7 = [45, 4, 9, 16, 25];
function myFunction7(total, value, index, array) {
  console.log(index,value,total);
  return total + value;
}
var sum7 = numbers7.reduceRight(myFunction7);


console.log(sum7);
console.log("=========================");

console.log('-----every--------');

var numbers8 = [45, 4, 9, 16, 25];
function myFunction8(value, index, array) {
  return value > 18;
}
var allOver18 = numbers8.every(myFunction8);

console.log(allOver18);
console.log("=========================");

console.log('-----some--------');

var numbers9 = [45, 4, 9, 16, 25];
function myFunction9(value, index, array) {
  return value > 18;
}
var someOver18 = numbers9.some(myFunction9);

console.log(someOver18);
console.log("=========================");

console.log('-----indexOf--------');

var fruits = ["Apple", "Orange", "Apple", "Mango"];
var a = fruits.indexOf("Apple");
console.log(a);
console.log("=========================");

console.log('-----lastIndexOf--------');

var fruits = ["Apple", "Orange", "Apple", "Mango"];
var a = fruits.lastIndexOf("Apple");
console.log(a);
console.log("=========================");

console.log('-----find--------');

var num1 = [4, 9, 16, 25, 29];
var first = num1.find(myFun1);

function myFun1(value, index, array) {
  return value > 18;
}
console.log(first);
console.log("=========================");

console.log('-----findIndex--------');

var first = num1.findIndex(myFun2);

function myFun2(value, index, array) {
  return value > 18;
}
console.log(first);
console.log("=========================");