Add solutions

Author: tshemsedinov

Solutions/1-for.js

@@ -0,0 +1,11 @@
+'use strict';
+
+const sum = (...args) => {
+  let value = 0;
+  for (let i = 0; i < args.length; i++) {
+    value += args[i];
+  }
+  return value;
+};
+
+module.exports = { sum };

Solutions/2-for-of.js

@@ -0,0 +1,9 @@
+'use strict';
+
+const sum = (...args) => {
+  let value = 0;
+  for (const arg of args) value += arg;
+  return value;
+};
+
+module.exports = { sum };

Solutions/3-while.js

@@ -0,0 +1,11 @@
+'use strict';
+
+const sum = (...args) => {
+  let value = 0;
+  while (args.length > 0) {
+    value += args.shift();
+  }
+  return value;
+};
+
+module.exports = { sum };

Solutions/4-do-while.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const sum = (...args) => {
+  if (args.length === 0) return 0;
+  let value = 0;
+  do {
+    value += args.shift();
+  } while (args.length > 0);
+  return value;
+};
+
+module.exports = { sum };

Solutions/5-reduce.js

@@ -0,0 +1,5 @@
+'use strict';
+
+const sum = (...args) => args.reduce((a, b) => (a + b), 0);
+
+module.exports = { sum };