JavaScript/Objects/Exercises

Topic: Objects

1. Be creative.

Create an object which describes some of your physical or mental attributes.
Show the object with the alert command.
Show only the most important attribute of this object with the alert command.
Add another property to the object. Show the complete object again.
Delete the least important attribute. Show the complete object again.

Click to see solution

"use strict";

// an example

// literal notation
const me = {height:"165 cm", weight: "63 kg", hairColor: "blond"};
alert(JSON.stringify(me));
alert(JSON.stringify(me.height));

me.friendliness = "medium";
alert(JSON.stringify(me));

delete me.hairColor;
alert(JSON.stringify(me));

2. Articles of a warehouse.

Create two objects shoe_1 and shoe_2 which characterize shoes. Use the literal notation.
Create two other objects shirt_1 and shirt_2 which characterize shirts. First, create empty objects. Then, add attributes to the objects.
Create an object warehouse and add all 4 objects to it.
Show the price of the 4.-th product out of the warehouse object.

Click to see solution

"use strict";

// literal notation
const shoe_1 = {category:"shoes", type: "sandals", size: 8, color: "brown"};
const shoe_2 = {category:"shoes", type: "high heels", size: 7, color: "silver", price: "94.50"};

// add properties
const shirt_1 = {};
shirt_1.category = "shirts";
shirt_1.size = "XL";
shirt_1["color"] = "blue";
shirt_1["material"] = "cotton";
alert(JSON.stringify(shirt_1));

// mixture
const shirt_2 = {size: "S", color: "green" };
shirt_2.category = "shirts";
shirt_2.price = 19.99;
alert(JSON.stringify(shirt_2));

const warehouse = {prod_1: {...shoe_1}, prod_2: {...shoe_2}, prod_3: {...shirt_1}, prod_4: {...shirt_2} };
alert(JSON.stringify(warehouse));

// the price of the 4.-th product
alert(JSON.stringify(warehouse.prod_4.price));

This example is not very elegant but shows different techniques. In a production environment, you probably would use loops and arrays.