Updated Function Exercises Morgan Griffiths

exercises/part1-fizzbuzz/index.js

@@ -33,3 +33,24 @@ Start code
 End code
 
 ===================== */
+
+// Step 1: Write a program that uses console.log to print each of the numbers from 1 to 100.
+for (let i = 1; i<= 100; i++){
+    console.log(i);
+}
+
+// Step 2: Update the program so that, for multiples of three, it prints "Fizz" instead of the number and, for multiples of five, it prints "Buzz" instead of the number.
+
+
+    // Step 3: For numbers which are multiples of *both* three and five, make the program print "FizzBuzz" instead of "Fizz" or "Buzz".
+    for (let i = 1; i<= 100; i++){
+        if (i % 3 == 0 && i % 5 == 0) {
+            console.log('FizzBuzz');
+        } else if (i % 3 == 0) {
+            console.log('Fizz');
+        } else if (i % 5 == 0) {
+            console.log('Buzz');
+        } else {
+            console.log(i);
+        }
+        }

exercises/part2-basic-functions/index.js

@@ -13,7 +13,10 @@ in years. (Let's just assume this person was born January 1 at 12:01 AM)
 Example: "age(2000) should return 22"
 ===================== */
 
-let age = (birthYear) => {};
+let age = (birthYear) => {
+    let age2 = 2022 - birthYear;
+    return age2;
+};
 
 console.log('age success:', age(1971) === 51);
 
@@ -22,7 +25,9 @@ Instructions: Write a function that adds one to the number provided
 Example: "plusOne(2) should return 3"
 ===================== */
 
-let plusOne = () => {};
+let plusOne = n => {
+    return n + 1;
+};
 
 console.log('plusOne success:', plusOne(99) === 100);
 
@@ -31,7 +36,7 @@ Instructions: Write a function that multiplies the number provided by three
 Example: "timesThree(2) should return 6"
 ===================== */
 
-let timesThree = () => {};
+let timesThree = (n) => { return n*3 };
 
 console.log('timesThree success:', timesThree(33) === 99);
 
@@ -40,7 +45,7 @@ Instructions: Write a function that adds two given numbers
 Example: "add(2, 3) should return 5"
 ===================== */
 
-let add = () => {};
+let add = (num1, num2) => { return num1 + num2};
 
 console.log('add success:', add(4, 6) === 10);
 
@@ -49,16 +54,19 @@ Instructions: Write a function that multiplies two given numbers
 Example: "multiply(2, 3) should return 6"
 ===================== */
 
-let multiply = () => {};
+let multiply = (num1, num2) => { return num1*num2 };
 
 console.log('multiply success:', multiply(4, 6) === 24);
 
 /* =====================
 Instructions: "Write a function that returns the value of an array at a specified index"
 Example: "valueAtIndex(['Mercury', 'Venus', 'Earth', 'Mars'], 2) should return 'Earth'"
 ===================== */
+const numArray = [9, 8, 7, 6, 5];
 
-let valueAtIndex = () => {};
+let valueAtIndex = (numArray, index) => {
+    return (numArray[index]);
+};
 
 console.log('valueAtIndex success:', valueAtIndex([9, 8, 7, 6, 5], 2) === 7);
 
@@ -67,22 +75,36 @@ Instructions: "Write a function that returns the value of an object at a specifi
 Example: "valueAtKey({'name': 'Nathan'}, 'name') should return 'Nathan'"
 ===================== */
 
-let valueAtKey = () => {};
+let valueAtKey = (obj, key) => {
+    return obj[key];
+};
 
 console.log('valueAtKey success:', valueAtKey({ 'foo': 'bar' }, 'foo') === 'bar');
 
 /* =====================
 Instructions: Write a function that returns true if a number is even.
 ===================== */
 
-let isEven = () => {};
+let isEven = (n) => {
+    if (n%2 == 0) {
+        return true;
+    } else {
+        return false;
+    }
+};
 
 console.log('isEven success:', isEven(2) === true && isEven(3) === false);
 
 /* =====================
 Instructions: Write a function that returns true if a number is odd.
 ===================== */
 
-let isOdd = () => {};
+let isOdd = (n) => {
+    if (n%2 != 0) {
+        return true;
+    } else {
+        return false;
+    }
+};
 
 console.log('isOdd success:', isOdd(4) === false && isOdd(5) === true);

exercises/part3-iterators/index.js

@@ -16,7 +16,15 @@ Instructions: Write a function which counts the number of times a value occurs i
 Example: countItem(['a', 'b', 'a'], 'a') should return 2
 ===================== */
 
-let countItem = (arr, item) => {};
+let countItem = (arr, item) => {
+  let count = 0;
+  for(let i = 0; i < arr.length; i++) {
+  if (arr[i] === item) {
+    count = 1 + count;
+  }
+  } return count;
+};
+
 
 console.log('countItem success:', countItem([1, 2, 3, 4, 5, 4, 4], 4) === 3);
 
@@ -27,8 +35,23 @@ Instructions: Write a function which takes an array and returns a new array with
   original array.
 ===================== */
 
-let isEven = (n) => {};
-let filterEven = (arr) => {};
+let isEven = (n) => {
+  if (n%2 == 0) {
+      return true;
+  } else {
+      return false;
+  }
+};
+
+
+let filterEven = (arr) => {
+  const evenArr = [];
+   for( let i=0; i<arr.length; i+=1) {
+    if(isEven(arr[i]) == true)
+    {evenArr.push(arr[i])}
+   }
+   return evenArr;
+  };
 
 console.log('filterEven success:', _(filterEven([1, 2, 3, 4, 5, 4, 4])).isEqual([2, 4, 4, 4]));
 
@@ -38,8 +61,22 @@ Instructions: Write a function which takes an array and returns a new array with
   function MUST use the isOdd function and MUST NOT change the original array.
 ===================== */
 
-let isOdd = (n) => {};
-let filterOdd = (arr) => {};
+let isOdd = (n) => {
+  if (n%2 != 0) {
+      return true;
+  } else {
+      return false;
+  }
+};
+
+let filterOdd = (arr) => {
+  const oddArr = [];
+  for( let i=0; i<arr.length; i+=1) {
+   if(isOdd(arr[i]) == true)
+   {oddArr.push(arr[i])}
+  }
+  return oddArr;
+ };
 
 console.log('filterOdd success:', _(filterOdd([1, 2, 3, 4, 5, 4, 4])).isEqual([1, 3, 5]));
 
@@ -50,8 +87,16 @@ Instructions: Write a function which takes an array and returns a new array with
   original array.
 ===================== */
 
-let plusOne = (n) => {};
-let mapIncrement = (arr) => {};
+let plusOne = n => {
+  return n + 1;
+};
+
+let mapIncrement =(arr) => {
+  const plusOneArr = [];
+  for( let i=0; i<arr.length; i+=1) {
+   plusOneArr.push(plusOne(arr[i]));
+ } return plusOneArr;
+};
 
 console.log('mapIncrement success:', _(mapIncrement([1, 2, 3, 4, 5, 4, 4])).isEqual([2, 3, 4, 5, 6, 5, 5]));
 
@@ -62,8 +107,14 @@ Instructions: Write a function which takes an array and returns a new array with
   original array.
 ===================== */
 
-let timesThree = (n) => {};
-let mapTriple = (arr) => {};
+let timesThree = (n) => { return n*3 };
+
+let mapTriple =(arr) => {
+  const timesThreeArr = [];
+  for(let i=0; i<arr.length; i+=1) {
+   timesThreeArr.push(timesThree(arr[i]));
+ } return timesThreeArr;
+};
 
 console.log('mapTriple success:', _(mapTriple([1, 2, 3, 4, 5, 4, 4])).isEqual([3, 6, 9, 12, 15, 12, 12]));
 
@@ -74,8 +125,15 @@ Instructions: Write a function which takes an array and returns the sum of all
   array.
 ===================== */
 
-let add = (n1, n2) => {};
-let reduceSum = (arr) => {};
+let add = (num1, num2) => { return num1 + num2};
+
+
+let reduceSum = (arr) => {
+  let sum = 0;
+  for(let i=0; i<arr.length; i+=1) {
+      sum = add(sum, arr[i]);
+  } return sum;
+};
 
 console.log('reduceSum success:', reduceSum([1, 2, 3, 4, 5, 4, 4]) === 23);
 
@@ -86,7 +144,12 @@ Instructions: Write a function which takes an array and returns the product of
   original array.
 ===================== */
 
-let multiply = (n1, n2) => {};
-let reduceProduct = (arr) => {};
+let multiply = (num1, num2) => { return num1*num2 };
 
-console.log('reduceProduct success:', reduceProduct([1, 2, 3, 4, 5, 4, 4]) === 1920);
+let reduceProduct = (arr) => {
+  let product = 1;
+  for(let i=0; i<arr.length; i+=1) {
+      product = multiply(product, arr[i]);
+  } return product;
+};
+console.log('reduceProduct success:', reduceProduct([1, 2, 3, 4, 5, 4, 4]) === 1920);

exercises/part4-functions-as-values/index.js

@@ -16,8 +16,14 @@ Instructions: Write a function which takes an array and returns a new array,
   function that takes one item as input and returns either true or false based
   on whether the item satisfies some condition).
 ===================== */
-
-let filter = (arr, pred) => {};
+let filter = (arr, pred) => {
+  const newArr = [];
+  for (let i = 0; i <arr.length; i+=1) {
+    if (pred(arr[i])) {
+      newArr.push(arr[i]);
+    }
+  } return newArr;
+};
 
 console.log('filter success #1:', _(filter([1, 2, 3, 4, 5, 4, 4], isEven)).isEqual([2, 4, 4, 4]));
 console.log('filter success #2:', _(filter([1, 2, 3, 4, 5, 4, 4], isOdd)).isEqual([1, 3, 5]));
@@ -27,7 +33,14 @@ Instructions: Write a function which takes an array and returns a new array,
   where each item has a function applied to it.
 ===================== */
 
-let map = (arr, func) => {};
+
+
+let map = (arr, func) => {
+  const newArr = [];
+  for( let i=0; i< arr.length; i+=1) {
+    newArr.push(func(arr[i]));
+  } return newArr;
+ };
 
 console.log('map success #1:', _(map([1, 2, 3, 4, 5, 4, 4], plusOne)).isEqual([2, 3, 4, 5, 6, 5, 5]));
 console.log('map success #2:', _(map([1, 2, 3, 4, 5, 4, 4], timesThree)).isEqual([3, 6, 9, 12, 15, 12, 12]));
@@ -52,7 +65,13 @@ Instructions: Write a function which takes an array and returns the value of
 
 ===================== */
 
-let reduce = (arr, func, initial) => {};
+let reduce = (arr, func, initial) => {
+  let n = initial;
+  for (let i = 0; i< arr.length; i+=1) {
+    n = func.call(undefined, n, arr[i], i, arr);
+  }
+  return n;
+};
 
 console.log('reduce success #1:', reduce([1, 2, 3, 4, 5, 4, 4], add, 0) === 23);
 console.log('reduce success #2:', reduce([1, 2, 3, 4, 5, 4, 4], multiply, 1) === 1920);
@@ -65,6 +84,6 @@ Bonus: Create a function called sumSquares that takes an array and returns
   `multiply` functions that you developed before).
 ===================== */
 
-let sumSquares = (arr) => {};
+let sumSquares = arr => arr.reduce((a, num) => a + num **2, 0);
 
 console.log('sumSquares success:', sumSquares([1, 2, 3, 4]) === 30);