+ 1
Guys can you help me to understand Constructors im kinda confuse of it i need a little help....
Tnx guys
2 Respostas
+ 12
As @Jay said, we can't create an object without calling constructor.
Some key points:
1. Constructor name must be same as the class name
2. Although constructor can be considered as a special kind of method, there will be no return type (not even void). This is how we can distinguish between a constructor and a general method.
Person() // this is a constructor
void Person() // this is a method
3. Constructor may or may not have any parameter. If you do not write any constructor, a no-arg constructor will work by default.
4. You can write multiple constructors by overloading if required.
Person()
Person(String name)
Person(String name, int age)
Person(int age)
....
Example:
If Person is a class with member variables: name and age, then constructor should look like:
Person(){ // without argument
}
or,
Person(String n, int a) // with argument
name = n;
age = a;
}
or, similar overloaded constructors.....
Now, while creating object, you must call any constructor using "new" keyword.
Person p = new Person();
or,
Person p = new Person("Rickyy", 15);
// "Rickyy" and 15 will be passed to the constructor as name and age and assign the values
+ 8
In c++ Constructors are used (called) when a class object is first instanced.
They are useful for setting any variables or parameters the object may need to function correctly.
Pretty sure the same goes for Java