Kajol1106 / java-8-features

java-8-features

Lambda Expression :

• Anonymous function (don't have any name and return type)
• applicable for functional interface.
• functional interface-> contains only one abstract method but can have multiple default and static method ex., Runnable=> run(), Callable=>call()
• with lambda expression we don't have to need method name and return type
• also you don't need to implement interface if there is only one method
• if there is only one statement then no need to bracket also

1. Example for single statement :

public interface Calculator {
	void switchOn();
}

public class LambdaMain{
	public static void main(String[] args) {
		Calculator c = () -> System.out.println("switch on method...");
		c.switchOn();
	}
}

2. Example for taking one argument :

public interface Calculator {
	void sum(int a);
}

public class LambdaMain{
	public static void main(String[] args) {
		Calculator c = (a) -> System.out.println("Sum = "+a);
		c.sum(5);
	}
}

3. Example for taking multiple arguments :

public interface Calculator {
	void multiply(int a, int b);
}

public class LambdaMain{
	public static void main(String[] args) {
		Calculator c = (a, b) -> {
			int res = a*b;
			System.out.println("Result is : "+res);
		};
		c.multiply(5, 4);
	}
}

4. Example for return statement :

public interface Calculator {
	intsubstraction(int a, int b);
}

public class LambdaMain{
	public static void main(String[] args) {
		Calculator c = (a, b) -> a-b;
		System.out.println(c.substraction(10, 5));
	}
}