The following lines of code create an object named myObject without any specific properties or methods. This line checks the type of the variable (myObject) and then prints the key-value pairs that define the object on the JavaScript console:

var myObject = {};
typeof(myObject);
myObject

The preceding lines created an empty object. Therefore, the result of the last line shows Object {} on the console. There are no properties or methods defined in the object. However, if we enter myObject. (myObject followed by a dot) in a JavaScript console with autocomplete features, we will see many properties and methods listed, as shown in the following screenshot. The object includes many built-in properties and methods:

The following lines of code create an object named myRectangle with two key-value pairs enclosed within a pair of curly braces ({}). A colon (:) separates the key from the value and a comma (,) separates the key-value pairs. The next line...