MYs

Question 1

myFind(array, callback)

Answer 1

function myFind (array, callback) {
  for (let i = 0; i < array.length; i++) {
    if (callback(array[i])) {
      return array[i];
    }
  }
}

Question 2

mySome

Answer 2

Array.prototype.mySome = function (callback) {
  let some = false;

this.myEach(el => {
if (callback(el)) some = true;
});

return some;
};

Question 3

myRotate

Answer 3

Array.prototype.myRotate = function (times = 1) {
  let rotations;
  const rotated = this.slice(0);

  if (times < 0) {
    rotations = this.length + (times % this.length);
  } else {
    rotations = times % this.length;
  }

  for (let i = 0; i < rotations; i++) {
    rotated.push(rotated.shift());
  }

return rotated;
};

Question 4

mySlice

Answer 4

String.prototype.mySlice = function(start, end) {
  let slice = "";

if (typeof end === ‘undefined’) {
end = this.length;
}

  for (let i = start; i < end && i < this.length; i++) {
    slice += this[i];
  }
  return slice;
};

Question 5

myReverse(array)

Answer 5

function myReverse(array) {
  const result = [];
  for (let i = 1; i < array.length + 1; i++) {
    result[i - 1] = array[array.length - i];
  }

return result;
}

Question 6

myReduce

Answer 6

Array.prototype.myReduce = function (callback, acc) {
  const array = this.slice();
  if (typeof acc === 'undefined') {
    acc = array.shift();
  }

array.myEach(el => {
acc = callback(acc, el);
});

return acc;
};

Question 7

myReject

Answer 7

Array.prototype.myReject = function (callback) {
  const selection = [];

  this.myEach(el => {
    if (!callback(el)) {
      selection.push(el);
    }
  });

return selection;
};

Question 8

myJoin

Answer 8

Array.prototype.myJoin = function (separator = '') {
  let newString = '';

this.forEach( (el, idx) => {
newString += ${el};
if (idx < this.length - 1) newString += separator;
});

return newString;
};

Question 9

myFlatten

Answer 9

Array.prototype.myFlatten = function () {
  let flattened = [];

  this.forEach((el) => {
    if (el instanceof Array) {
      flattened = flattened.concat(el.myFlatten());
    } else {
      flattened.push(el);
    }
  });

return flattened;
};

Question 10

myFilter

Answer 10

Array.prototype.myFilter = function (callback) {
  const result = [];

this.myEach((el) => {
if (callback(el)) result.push(el)
});

return result;
};

Question 11

myEvery

Answer 11

Array.prototype.myEvery = function (callback) {
  let every = true

this.myEach(el => {
if (!callback(el)) every = false;
});

return every;
};

Question 12

myEach

Answer 12

Array.prototype.myEach = function (func) {
  for (let i = 0; i < this.length; i++) {
    func(this[i]);
  }
};

Question 13

myCurry

Answer 13

Function.prototype.myCurry = function (numArgs) {
  let nums = [];
  let fcn = this;
  return function _myCurry (el) {
    nums.push(el);
    if (nums.length < numArgs) {
      return _myCurry;
    } else {
      return fcn(...nums);
    }
  };
};

Question 14

myBind

Answer 14

Function.prototype.myBind = function (context, ...bindArgs) {
  const that = this;
  return function (...callArgs) {
    return that.apply(context, bindArgs.concat(callArgs));
  };
};

Question 15

myCall

Answer 15

Function.prototype.myCall = function (context, …args) {
return this.bind(context)(…args);
};

// Also works (passing arguments at bind-time vs call-time)
Function.prototype.myCall = function (context, ...args) {
  return this.bind(context, ...args)();
};

Question 16

myApply

Answer 16

Function.prototype.myApply = function (context, args = []) {
return this.bind(context)(…args);
};

// Also works (passing arguments at bind-time vs call-time)
Function.prototype.myApply = function (context, args = []) {
  return this.bind(context, ...args)();
};