adding exercies for steps 2-1 and 2-2

step2-01/demo/src/spread/index.ts

@@ -0,0 +1,24 @@
+// Destructuring
+var [a, b, ...rest] = [1, 2, 3, 4];
+console.log(a, b, rest); // 1,2,[3,4]
+
+// Array assignment
+var list = [1, 2];
+list = [...list, 3, 4];
+console.log(list); // [1,2,3,4]
+
+// Object assignment
+const point2D = { x: 1, y: 2 };
+const point3D = { ...point2D, z: 3 };
+
+// Concat two objects
+const obj1 = { x: 1 };
+const obj2 = { y: 2 };
+
+const obj3 = { ...obj1, ...obj2 };
+
+// Destructuring object
+const { x } = obj3;
+
+// adding an export to turn this into a "module"
+export default {};