Good solution for matrix(6-matrix.js)

Author: VladyslavHolik

Exercises/1-for.js

@@ -1,9 +1,12 @@
 '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;
+  if (args) {
+  for (let i = 0; i < args.length; i++) {
+    res += args[i];
+  }}
+  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;
+ if (args) {
+   for (const value of args) res += value;
+ }
+ return res;
 };
 
 module.exports = { sum };

Exercises/3-while.js

@@ -1,9 +1,12 @@
 '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;
+  if (args) {
+    let i = 0
+    while (i < args.length) res += args[i++];
+  }
+  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[0]) { let i = 0;
+    do {
+      res += args[i];
+      i = i + 1;
+    } while (i < args.length);
+  };
+  return res;
 };
 
 module.exports = { sum };

Exercises/5-reduce.js

@@ -1,8 +1,6 @@
 '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((acc, x) => acc + x, 0);
+
 
 module.exports = { sum };

Exercises/6-matrix.js

@@ -1,9 +1,15 @@
 '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 list = [];
+  for (let elem of matrix) {
+    for (let inside of elem) {
+      list.push(inside);
+    }
+  }
+  // easy gggggggggggggggggggggggggggggggg
+  return list.reduce((acc, x) => acc > x ? acc : x);
 };
 
+
 module.exports = { max };

Exercises/7-ages.js

@@ -1,19 +1,12 @@
 '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 res = {};
+  for (const key in persons) {
+    // value = date of death - date of birth
+    res[key] = persons[key].died - persons[key].born;
+  }
+  return res;
 };
 
 module.exports = { ages };