java-mod-4-lambda-expression-lab's Introduction

Lambda Expression Lab

Instruction

Do not create a new class. Use a lambda expression to implement the interface.

TASK #1:

Functional interface MyIntOperator defines an abstract method named apply:

@FunctionalInterface
public interface MyIntOperator {
    int apply(int x);
}

Task1.java declares a variable named nextInt and assigns the variable to null:

public static MyIntOperator nextInt = null ; //replace null with lambda expression

Edit Task1.java to replace the null value with a lambda expression that implements MyIntOperator. The lambda expression should increment the parameter by 1.

NOTE: The nextInt variable is defined as public static so the Junit test can access and test the lambda expression.

Run the program and confirm the output:

Run the Junit test Task1Test to confirm your implementation.

TASK #2:

Functional interface MyIntPredicate defines abstract method test:

@FunctionalInterface
public interface MyIntPredicate {
    boolean test(int x);
}

Edit Task2.java to replace the null value with a lambda expression that implements MyIntPredicate.
The lambda expression should test whether the parameter is an even number.

public static MyIntPredicate isEven = null ; //replace null with lambda expression

Run the program and confirm the output:

true
false
false
true

Run the Junit test Task2Test to confirm your implementation.

TASK #3:

Edit Task3.java to replace the null value with a lambda expression that implements MyIntOperator.
The lambda expression should return the next odd number that follows the parameter value.

public static MyIntOperator nextOdd = null; //replace null with lambda expression

Run the program and confirm the output: