Add for..in task

Author: tshemsedinov

Exercises/7-ages.js

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+'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,
+  // }
+};
+
+module.exports = { ages };

Exercises/7-ages.test

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+({
+  name: 'ages',
+  length: [150, 190],
+  cases: [
+    [
+      {
+        lenin: { born: 1870, died: 1924 },
+        mao: { born: 1893, died: 1976 },
+        gandhi: { born: 1869, died: 1948 },
+        hirohito: { born: 1901, died: 1989 },
+      }, {
+        lenin: 54,
+        mao: 83,
+        gandhi: 79,
+        hirohito: 88,
+      }
+    ]
+  ],
+  test: ages => {
+    const src = ages.toString();
+    if (!src.includes('for (')) throw new Error('Use for..in loop');
+    if (!src.includes(' in ')) throw new Error('Use for..in loop');
+  }
+})

Solutions/7-ages.js

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+'use strict';
+
+const ages = persons => {
+  const data = {};
+  for (const name in persons) {
+    const person = persons[name];
+    data[name] = person.died - person.born;
+  }
+  return data;
+};
+
+module.exports = { ages };