Short questions on Java Functions

1. Give the output and what does this test function do?

public class output3
{
void test()
{
int n=5732,result=0;
do
{
result *= 10;
int digit = n%10;
result += digit ;
n = n/10;
}while(n>0);
System.out.println(“Output = ” + result);
}
}

Ans

2375                 (it reverse the number.)

2. In the program given below, state the name and the value of the function :

1. 1. method argument or argument variable
   2. local variable
   3. class variable
   4. instance variable

class myClass{
static int x = 7; int y = 2;
public static void main(String args[] ){
myClass obj= new myClass();
System.out.println( x );
obj.sampleMethod(5);
int a = 6;
System.out.println( a );
}
void sampleMethod(int n){
System.out.println(n);
System.out.println(y);
}
}

Ans

1. 1. Method argument or argument variable is: n
   2. The class variable is : x
   3. The local variable is: a
   4. The instance variable is: y

3. Write the prototype of a function ADD() for each of the following purpose:

1. 1. To return and integer value.
   2. To receive one integer, one double type argument and returns a double type value
   3. To receive a character and an integer as parameters and no returning
   4. To receive an integer as parameter and returns true or false.

Ans.

1. 1. public int ADD) or public static int ADD) or int ADD)
   2. public double ADD ( int y, double m) or public static double ADD( int y, double m) or double ADD( int y, double m)
   3. public void ADD( char ch, int y) or public static void ADD( char ch, int y) or void ADD( char ch, int v)
   4. public boolean ADD( int y) or public static boolean ADD( int y) or boolean ADD( int y)

4. Write the prototype of a method stud() which takes a string argument and a character argument and returns an integer.

Ans.

public static int stud ( String str, char ch ) OR
public int stud ( String str, char ch) OR
int stud ( String str, char ch)

5. Write the prototype of a function Count which takes character argument and string argument and returns a true or false.

Ans.

public static boolean Count( char ch, String str ) OR
public boolean Count (char ch, String str) OR
boolean Count(char ch, String str )

6. What are the values of a and b after the following function is executed, if the values passed are 30 and 50:

void paws(int a, int b)
{
a = a + b;
b = a – b;
a = a – b;
}

Ans. a=50 and b=30

7. In the program given below, state the name and the value of the :

1. 1. method argument or argument variable
   2. local variable
   3. class variable
   4. instance variable

class myClass{
static int x = 7; int y = 2;
public static void main(String args[] ){
myClass obj= new myClass();
System.out.println( x );
obj.sampleMethod(5);
int a = 6;
System.out.println( a );
}
void sampleMethod(int n){
System.out.println(n);
System.out.println(y);
}
}

Ans.

1. 1. Method argument or argument variable is: n
   2. The class variable is : x
   3. The local variable is: a
   4. The instance variable is: y

8. Write a small program code to show function call by value method.

Ans.

class program{
public static void simply( int a, int b){
a= a/2;
b= b+10;
System.out.println("The value of A = " + a +" and B " + b);
}
public static void run(){       // this function calls the above function simply()
int x= 20, y= 10;
simply(x, y);                //calling  function simply()
}

9. Give the prototype of a function search which receives a sentence snt and a character ch and returns 1 or 0 ?

Ans.

public int function ( String snt, char ch )

10. Write a function prototype of the following:

A function PChar which takes an integer argument and a character argument and returns an integer value.

Ans.    public int PChar(int n, char c)