A lot of discussion has occurred about classes and objects, yet you still do not know how to create an object from a class definition!
To create a new object “of class type X”, you need to call the new keyword, followed by the name of the class, including any constructor input parameters within parentheses trailing the class name. This can then be assigned to a variable for later reference.
The following creates a new object, of class type ClassName, and passes it two input parameters. This new object is stored in the variable myObj.
let myObj = new ClassName( inputParam1, inputParam2 );
To access an objects properties, we will use the same “dot notation” as we learned about with objects data structures.
myObj.property1; // ← returns the value of 'myObj's property1.
We can also set object properties using this same notation.
myObj.anotherProperty = 23; // ← sets the value of the property to 23
NOTE: Typically, when using classes and OOP paradigms, setting object properties with this notation is considered poor style. This is because it can lead to errors in code. More on this will be discussed later.
dot notation is also used to execute object methods. However, parenthesis are always added to the method name, regardless of whether there are input parameters being passed to the method or not.
myObj.method1(); // ← executes myObj's method, 'method1'.
myObj.method2( inParam2, 57 ); // ← execute the method and pass it two input parameter values.