2.2 Creating & Initializing Objects: Constructors | CSAwesome APCSA Java смотреть онлайн

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Constructors initialize the attributes in newly created objects. They have the same name as the class.

A constructor signature is the constructor name followed by the parameter list which is a list of the types of the parameters and the variable names used to refer to them in the constructor.

Overloading is when there is more than one constructor. They must differ in the number, type, or order of parameters.

New is a keyword that is used to create a new object of a class. The syntax is new ClassName(). It creates a new object of the specified class and calls a constructor.

A no-argument constructor is a constructor that doesn’t take any passed in values (arguments).

Parameters allow values to be passed to the constructor to initialize the newly created object’s attributes.

The parameter list, in the header of a constructor, is a list of the type of the value being passed and a variable name. These variables are called the formal parameters.

Actual parameters are the values being passed to a constructor. The formal parameters are set to a copy of the value of the actual parameters.

Formal parameters are the specification of the parameters in the constructor header. In Java this is a list of the type and name for each parameter (World(int width, int height).

Call by value means that when you pass a value to a constructor or method it passes a copy of the value.