Variables Accessible in a Lambda Expression in Java

The lambda expressions consist of two parts, one is parameter and another is an expression and these two parts have separated by an arrow (->) symbol. A lambda expression can access a variable of it's enclosing scope. 

A Lambda expression has access to both instance and static variables of it's enclosing class and also it can access local variables which are effectively final or final.

Syntax

( argument-list ) -> expression

Example

interface TestInterface {
   void print();
}
public class LambdaExpressionTest {
   int a; // instance variable
   static int b; // static variable
   LambdaExpressionTest(int x) {    // constructor to initialise instance variable
      this.a = x;
   }
   void show() {
      // lambda expression to define print() method
      TestInterface testInterface = () -> {
      // accessing of instance and static variable using lambda expression
         System.out.println("Value of a is: "+ a);
         System.out.println("Value of b is: "+ b);
      };
      testInterface.print();
   }
   public static void main(String arg[]) {
      LambdaExpressionTest test = new LambdaExpressionTest(10);
      test.show();
   }
}

Output

Value of a is: 10
Value of b is: 0