Constructors and Parameterized Constructors

Object Initialization:
Constructors are special methods that initialize objects when they are created.
They have the same class name and have no return type.

Utility:
Constructors are used to provide initial values ​​to instance variables or perform other initialization tasks.

Default Constructor:
If a class does not define a constructor, Java automatically provides a default constructor.
This default constructor initializes numeric variables to zero, references to null and booleans to false.

Example:
The MyClass class has a constructor that initializes the instance variable x with the value 10.

// Um construtor simples.
class MyClass {
    int x;

    // Construtor da classe MyClass
    MyClass() {
        x = 10; // Inicializa x com 10
    }
}

class ConsDemo {
    public static void main(String args[]) {
        MyClass t1 = new MyClass(); // Cria uma instância de MyClass
        MyClass t2 = new MyClass(); // Cria outra instância de MyClass

        // Exibe os valores de x para ambas as instâncias
        System.out.println(t1.x + " " + t2.x);
    }
}

Parameterized Constructors

• Need for Parameters: Parameterized constructors allow initializing objects with different values. They accept parameters in the same way as methods, declared inside parentheses after the constructor name.

Example:
The MyClass class has a parameterized constructor that accepts an integer i and initializes x to that value.
When creating objects, different values ​​can be passed to initialize x with specific values.
These topics highlight the importance of constructors for the safe and correct initialization of objects, in addition to allowing the creation of instances with different initial states.

// Um construtor parametrizado.
class MyClass {
    int x;

    // Construtor parametrizado da classe MyClass
    MyClass(int i) {
        x = i; // Inicializa x com o valor passado no parâmetro i
    }
}

class ParmConsDemo {
    public static void main(String args[]) {
        MyClass t1 = new MyClass(10); // Cria uma instância de MyClass com x = 10
        MyClass t2 = new MyClass(88); // Cria outra instância de MyClass com x = 88

        // Exibe os valores de x para ambas as instâncias
        System.out.println(t1.x + " " + t2.x);
    }
}

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