Java Lambda Expression Example

The biggest new feature of java-8 is Lambda Expression. It simplifies the development a lot means it cut lines of code. The syntax for it is “parameters -> body” , Some important rules to syntax is : 

1 > Declaring the types of the parameters is optional.

2 > Using parentheses around the parameter is optional if you have only one parameter.

3 > Using curly braces is optional (unless you need multiple statements).

4 > The “return” keyword is optional if you have a single expression that returns a value.

interface MathOperation{

int operation(int a,int b);

}

public class LambdaExample {

public static void main(String[] args) {

// with variable type declaration

MathOperation add = (int a,int b) -> a+b;

System.out.println("ADDITION\t:"+add.operation(5, 2));

// without variable type declaration

MathOperation sub = (a,b) -> a-b;

System.out.println("SUBSTRACTION\t:"+sub.operation(5, 3));

// with return statement along with curly braces

MathOperation div = (a,b) -> {return a/b ; };

System.out.println("DIVIDE\t\t:"+div.operation(10, 5));

// Traversing Arraylist in one line

List<Integer> l=new ArrayList<Integer>();

for(int i=0;i<10;i++){

l.add(i);

}

l.forEach( n -> System.out.println(n));

// Providing the type of parameter is optional 

l.forEach((Integer n) -> System.out.println(n));

// Sorting Arraylist using Lambda Expression in one line

List<Integer> list = new ArrayList<>();

list.add(2);

list.add(5);

list.add(3);

Collections.sort(list , (i,j) -> i.compareTo(j));

System.out.println("SORTED LIST : "+list);

  // Starting Thread using lambda expression

new Thread( () -> System.out.println("In Java8, Lambda expression rocks !!") ).start();

}

}