Compile-time polymorphism in Java - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a method named add that takes two integers and returns their sum.

Java

public int add(int a, int b) {
    return a [1] b;
}

Drag options to blanks, or click blank then click option'

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication instead of addition.

The add method should return the sum of a and b. The plus sign + adds two numbers.

2fill in blank

medium

Complete the code to overload the add method to accept two double values.

Java

public double add(double a, double b) {
    return a [1] b;
}

Drag options to blanks, or click blank then click option'

A-

B*

C+

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using operators other than addition.

The overloaded add method should add two double values using the + operator.

3fill in blank

hard

Fix the error in the method signature to correctly overload the add method with three integer parameters.

Java

public int add(int a, int b, [1] c) {
    return a + b + c;
}

Drag options to blanks, or click blank then click option'

Aint

Bdouble

CString

Dfloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different data type like double or String for the third parameter.

The method overload requires three integer parameters, so the third parameter must be int.

4fill in blank

hard

Fill both blanks to create two overloaded multiply methods: one for two integers and one for two doubles.

Java

public int multiply(int a, int b) {
    return a [1] b;
}

public double multiply(double a, double b) {
    return a [2] b;
}

Drag options to blanks, or click blank then click option'

A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition or division instead of multiplication.

Both methods multiply their parameters using the * operator.

5fill in blank

hard

Fill all three blanks to create overloaded concatenate methods: one for two strings, one for three strings, and one for an array of strings.

Java

public String concatenate(String a, String b) {
    return a [1] b;
}

public String concatenate(String a, String b, String c) {
    return a [2] b [3] c;
}

Drag options to blanks, or click blank then click option'

A+

B-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using arithmetic operators other than plus for strings.

String concatenation in Java uses the + operator to join strings.