Question

When are values passed as parameters?

a. When parameters are primitives or wrappers

b. When parameters are user-defined objects

c. When parameters are objects

What is the result of a == b?

public static void main(String[] args) {

int[] a = {1, 2, 3};

int[] b = {1, 2, 3};

}

a. True

b. False

c. Compile Error

Answer 1

I have explained all the three parameters along with examples in order to make it clear.

Second question , answer is false .

I have provided reasoning .

If you have nay problem, feel free to ask.

Explanation:

Ans (a)

When parameters are primitive , then we can pass values with primitive data types like (int , short int , long , double , float , char , boolean, byte )

For eg:

int Sum( int a , int b)

return a+b;

Here a and b are primitive parameters

Ans (b)

When parameters are user defined objects , they are passed using constructor function.

For eg:

Class sum()

{

int sum( int a , int b)

{

this.a = 5;

this.b = 7;

return a+b;

}

Here a and b are user defined objects.

Ans (c)

Objects as parameters can also be passed in java , in any function.

For eg:

Class student {

import java.util.Scanner;

public class Student {

  private String name;

  private int age;

  public Student(){

  }

  public Student(String name, int age){

   this.name = name;

   this.age = age;

  }

  public Student copyObject(Student std){

   this.name = std.name;

   this.age = std.age;

   return std;

  }

  public void displayData(){

   System.out.println("Name : "+this.name);

   System.out.println("Age : "+this.age);

  }

Here copyobject() function takes objects of student class (std) as parameter.( I have boldened it to highlight)

Q- Result of a==b

(b) False

The result is false because these two arrays are reference to two different objects and when we use comparison operator(==), it compares reference variables. Therefore the result is false .

But if we want to compare two arrays in java, a method called Arrays . equals() is provided . We may pass arrays as parameters , in order to compare.