map init

5.6Map/t.js

@@ -0,0 +1,18 @@
+let map = new Map();
+
+map.set('1', 'first');
+map.set(1, 'second');
+map.set(true, 'third');
+
+console.log(map.get('1'));
+console.log(map.get(1));
+console.log(map.get(true));
+
+console.log(map.size);
+
+// we should use the map.get() method, not map[] so that we can use the feature of the map, ot the map can only get the value from number and string
+
+let person = {name: 'John'};
+map.set(person, 'hi');
+console.log(map.get(person));
+