Javascript Array myMap(callback)

var s = [23, 65, 98, 5];

Array.prototype.myMap = function(callback) {
  var newArray = [];

  s.forEach(a => {//from   ww w  .  j ava2 s .  c  o  m
    newArray.push(callback(a));
  });

  return newArray;
};

var new_s = s.myMap(function(item) {
  return item * 2;
});

console.log(new_s);

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

Array.prototype.myMap = function(callback){
  var result =[];
  for(var i=0; i<this.length; i++){
    result.push(callback(this[i]));//from www  .  j a va 2s . co  m
  }
  return result;
}

/*
 Best if you don't code out here.
 If you want to check your code, use `index.js`!
*/

// implement the Array.prototype.map function in JavaScript (es6)

// a for loop should suffice, iterate from 0 to the length of the
// array - 1 and call the function on it

Array.prototype.myMap = function(callback) {
    let mapped = [];
    for (let i = 0; i < this.length; i++) {
        mapped.push(callback(this[i]));//from w w  w  .  j a v  a 2 s  .co  m
    }
    return mapped;
};

console.log([1,2,3,4,5].myMap( (el) => Math.pow(el, 2)) );
console.log([].myMap( (el) => Math.pow(el, 2)) );
console.log([1,2,3,4,5].myMap( (el) => el));

// filter - Implement your owen Array.prototype.map function
// Solution - 1// ww w  .  ja va 2  s  .c o  m

Array.prototype.myMap = function (callback) {

 arr = []

 for (let i = 0; i < this.length; i++) {

  arr.push(callback(this[i], i, this));
 }
 return arr;
}

let numbers = [ 1, 4, 9 ] ;

let squareRoot = numbers.myMap(i => Math.sqrt(i))

console.log(squareRoot);  // => [ 1, 2, 3 ]


// Without using Array.prototype

myMap2 = (array, callback) => {

 let arr = [];

 for (let i = 0; i < array.length; i++) {
  arr.push(callback(array[i], i, this))
 }
 return arr;
}

let squareRoot1 = myMap2(numbers, (num) => {
 return Math.sqrt(num)
})

console.log(squareRoot1);  // => [ 1, 2, 3 ]

Array.prototype.myMap = function(callBack) {
  const newArr = [];/*from w  w  w  .  ja  v  a 2s. c  om*/

  this.myEach((el) => { newArr.push(callBack(el)); });

  return newArr;
};

// console.log([1,2,3,4,5].myMap((el) => {
//   return el * 3;
// }));

Array.prototype.myMap = function (callback) {
  var result = [];
  this.myEach(function(el) {
    result.push(callback(el));//ww w  .  ja  v a2  s .  c  o  m
  });
  return result;
}

var b = a.myMap(function (el) {
  return el * 2;
})
console.log(b);

Array.prototype.myMap = function(callback) {
    var newArray = []
    for (var i = 0, max = this.length; i < max; i++) {
        newArray.push(callback(this[i]))
    }//w w  w.  jav a  2  s.c  o  m
    return newArray
}
function upperNames(value) {
    return value.toUpperCase()
}
var newUpper = names.myMap(upperNames)
console.log(newUpper)

//Map Prototype/*w w w  .  j a v a  2  s.  c o  m*/
Array.prototype.myMap = function(callback) {
    var newArray = [];
    for(var i = 0; i < this.length; i++) {
        newArray.push(this[i].toUpperCase());
    }
    return newArray;
};

var mapArray = names.myMap();
console.log("Map Prototype: " + mapArray);

function isEven(n) {
  if (n === 0) {/*from   ww w.j  a v a  2 s .  c om*/
    return true;
  }
  else if (n === 1) {
    return false;
  }
  else {
    return isEven(n - 2);
  }
}

isEven(5);

Array.prototype.myMap = function(callback) {
  arr = [];
  for (var i = 0; i < this.length; i++) {
    arr.push(callback(this[i]));
  }
  return arr;
}

var doubled = [1,2,3].myMap(function(n) {
  return n ** 2;
});

console.log(doubled);


function rot13(str) { // LBH QVQ VG!
  
  var splitStr = str.split('');

  for (var i = 0; i < splitStr.length; i++) {
    if (splitStr[i] !== ' ') {
      splitStr[i] = splitStr[i].charCodeAt() + 13;
      if (splitStr[i] > 90) {
        splitStr[i] -= 26;
      }
      splitStr[i] = String.fromCharCode(splitStr[i]);
    }
  }
  
  return splitStr.join('');
}

// Change the inputs below to test
console.log(rot13("SERR PBQR PNZC"));