Add Exercises 1-2-3-4-5-6-7

Author: Mitya

Exercises/1-for.js

@@ -1,9 +1,11 @@
 'use strict';
 
 const sum = (...args) => {
-  // Use for loop and accumulator variable
-  // to calculate sum of all given arguments
-  // For example sum(1, 2, 3) should return 6
+  let res = 0;
+  for (let elem of args) {
+    res += elem;
+  }
+  return res;
 };
 
 module.exports = { sum };

Exercises/2-for-of.js

@@ -1,9 +1,11 @@
 'use strict';
 
 const sum = (...args) => {
-  // Use for..of loop and accumulator variable
-  // to calculate sum of all given arguments
-  // For example sum(1, 2, 3) should return 6
+  let res = 0;
+  for (const elem of args) {
+    res += elem;
+  }
+  return res;
 };
 
 module.exports = { sum };

Exercises/3-while.js

@@ -1,9 +1,13 @@
 'use strict';
 
 const sum = (...args) => {
-  // Use while loop and accumulator variable
-  // to calculate sum of all given arguments
-  // For example sum(1, 2, 3) should return 6
+  let res = 0;
+  let c = 0;
+  while (c < args.length) {
+    res += args[c];
+    c++;
+  }
+  return res;
 };
 
 module.exports = { sum };

Exercises/4-do-while.js

@@ -1,9 +1,14 @@
 'use strict';
 
 const sum = (...args) => {
-  // Use do..while loop and accumulator variable
-  // to calculate sum of all given arguments
-  // For example sum(1, 2, 3) should return 6
+  let res = 0;
+  if (args.length === 0) {
+    return 0;
+  }
+  do {
+    res += args.pop();
+  } while (args.length > 0);
+  return res;
 };
 
 module.exports = { sum };

Exercises/5-reduce.js

@@ -1,8 +1,5 @@
 'use strict';
 
-const sum = (...args) => 0;
-// Use Array.prototype.reduce method
-// to calculate sum of all given arguments
-// For example sum(1, 2, 3) should return 6
+const sum = (...args) => args.reduce((accum, val) => accum + val, 0);
 
 module.exports = { sum };

Exercises/6-matrix.js

@@ -1,9 +1,13 @@
 'use strict';
 
 const max = matrix => {
-  // Use nested for loop to find max value in 2d matrix
-  // For example max([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
-  // should return 9
+  let result = []
+  for (let elem = 0; elem < matrix.length; elem++) {
+    result.push(...matrix[elem]);
+  }
+  const maxValue = result.sort((a, b) => a - b).pop();
+  return maxValue;
+  //*******************
 };
 
 module.exports = { max };

Exercises/7-ages.js

@@ -1,19 +1,10 @@
 'use strict';
 
 const ages = persons => {
-  // Use for..in to calculate age for each person
-  // For example ages({
-  //   lenin: { born: 1870, died: 1924 },
-  //   mao: { born: 1893, died: 1976 },
-  //   gandhi: { born: 1869, died: 1948 },
-  //   hirohito: { born: 1901, died: 1989 },
-  // })
-  // should return {
-  //   lenin: 54,
-  //   mao: 83,
-  //   gandhi: 79,
-  //   hirohito: 88,
-  // }
+  const resultObj = {};
+  for (let key in persons) {
+    resultObj[key] = persons[key].died - persons[key].born;
+  }
+  return resultObj;
 };
-
 module.exports = { ages };