Computer Knowledge

Programming Output Evaluation

1,721 Questions

Programming output evaluation tests the ability to trace code execution in languages like C, Java, and SAS. It focuses on arrays, loops, pointers, and data type conversions. These technical questions are standard in computer knowledge sections for IT officer and bank exams.

Java string bufferC language pointersLoop execution outputsData type conversionsMacro variable evaluation

Programming Output Evaluation Questions

Multiple choice

What is the output of the given program code?

public class ScopeTest
{
public static void main(String[] args)
{
ScopeTest sc, scA, scB;
sc = new ScopeTest();
scA = new ScopeTestA();
scB = new ScopeTestB();
System.out.println("Hash is : " + sc.getHash() + ", " + scA.getHash() + ", " + scB.getHash());
}
public int getHash()
{
return 111111;
}
}
class ScopeTestA extends ScopeTest
{
public long getHash()
{
return 44444444;
}
}
class ScopeTestB extends ScopeTest
{
public long getHash()
{
return 999999999;
}
}

  1. Hash is: 111111, 44444444, 999999999

  2. Blank output screen

  3. An exception is thrown at runtime

  4. Compilation Fails

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct choice. The compilation fails as SampleClassA and SampleClassB cannot override SampleClass’s getHash() method because the return type of SampleClass’s getHash() method is int, while the return type of SampleClassA and SampleClassB is long. Note: If all three classes had the same return type, the output would be: Hash is : 111111, 44444444, 999999999 So, this is the correct choice.

Multiple choice

What is the output of the given program?

Int [] [] array = {{0}, {0, 1}, {0, 2, 4}, {0, 3, 6, 9}, {0, 4, 8, 12, 16}};
Systemout.printIn(array [2] [1]);
System.out.printIn (array) [2][4]);

  1. 1 null

  2. Null null

  3. 2 an ArrayIndexOutofbound Exception is thrown

  4. ArrayIndexOutofbound Exception is thrown

  5. Compilation fails
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct answer. The first println statement, System.out.println(array [2][1]), works fine. It selects the element/array with index 2, {0, 2,4}, and from this array it selects the element with index 1 which is 2. So, 2 gets printed. The second println statement, System.out.println(array) [2][4]), fails. It selects the array/element with index 2,{0, 2, 4}, and from this array, it tries to select the element with index 4. This causes an exception. So, an exception in thread main java.lang.ArrayIndexOutOfBoundsException occurs.

Multiple choice

What is the output of the given program?

class A
{
int a;
A(int a)
{
System.out.println(a);
}
public void display()
{
System.out.println("Hello");
}
}
class ScopeTest extends A
{
public static void main(String[] args)
{
ScopeTest s1 = new ScopeTest();
s1.display();
}
}

  1. Hello

  2. 0

  3. Run time error

  4. Compilation error

  5. Blank output screen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct choice. Class ScopeTest extends class A. When we create an object of class ScopeTest, it automatically calls the non-argument constructor of class A, but there is no such constructor in class A. So, the compiler will throw an error. If we add a non-argument constructor (as shown below) in class A, then the code will compile.A(){} So, this answer is true.

Multiple choice

How many times is 1 printed as a part of output?

public class ScopeTest
{
int z;
public static void main(String[] args)
{
String[] table = {"aa", "bb", "cc"};
for (String ss: table)
{
int ii = 0;
while (ii < table.length)
{
System.out.println(ss + ", " + ii); ii++;
}
}
}
}

  1. Zero times

  2. Once

  3. Twice

  4. Thrice

  5. Compilation fails
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct choice. For statement, (String ss: table), is executed one time for each of the three elements in table. The while loop will print 1 once for each element. The output comes out to be : aa, 0aa, 1aa, 2bb, 0bb, 1bb, 2cc, 0cc, 1cc, 2 So, 1 will be printed 3 times, hence this answer is correct.

Multiple choice

What will be the output of the given code?

String s = “Welcome To Java” s.substring(4, 4);

  1. o

  2. c

  3. Empty string

  4. Compile time error

  5. Run time error
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct answer. Substring method takes two parameters (BeginIndex, EndIndex).Substring(int Begin, int End). It returns the string from the beginning to end – 1. But if the BeginIndex is equal to the EndIndex, then an empty String with length 0 will be returned. So, here substring(4, 4) will return an empty string of length 0.  

Multiple choice

What will be the result of the following code?

String s = “Welcome To Java”; s.charAt(s.length());

  1. a

  2. v

  3. Compiler Error : cannot pass a function as parameter

  4. Compiler Error : parameters not sufficient

  5. Run time error
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct answer. s.length() will return 15 because there are 15 characters in the string. So, the code looks like this: s.charAt(15); the index count starts at 0. In this way, the last character is 'a' at index number 14. So, if we try to access a character in a string which is out of bound, then a runtime exception “StringIndexOutOfBound” will be thrown. So, we can pass only till s.charAt(s.length()-1).

Multiple choice

What will be the output of the given program? class BitShift { public static void main(String [] args) { int x = 0x80000000; System.out. print(x + and) ; x = x >>> 31; System.out. println(x); } }

  1. -2147483648 and 1

  2. 0x80000000 and 0x00000001

  3. -2147483648 and -1

  4. 1 and -2147483648

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option (1) is correct. The >>> operator moves all bits to the right, zero filling the left bits. The bit transformation looks like this: Before: 1000 0000 0000 0000 0000 0000 0000 0000 After: 0000 0000 0000 0000 0000 0000 0000 0001 Converting this into decimal, the result will be 2147483648 and 1 So, this is the correct choice.

Multiple choice

String s = “Welcome To Java” s.substring(4, 3 );

What will be the result of the above code?

  1. ome
    • 1

  3. com

  4. Runtime error

  5. Compile time error
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer. Substring method takes two parameters (beginIndex,EndIndex). Substring( int Begin , int End). It returns the string from begin to end -1. But if the begin index is greater than the end index then a runtime error will occur. So here substring(4,3) will give a runtime error.

Multiple choice

String s = “Welcome To Java”; String s1 = “Java”; s.match(s1);

What will be the output of the given piece of code?

  1. True

  2. False
    • 1

  4. Compile time error

  5. Runtime error
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer. The compiler will throw an error that method match() was not declared. Because String class does not contain any method named match(). The correct method is matches(). So the above statement should be s.matches(s1). So this is the correct answer. The program will not run. So run time error cannot occur because a compiler error is there. So this is wrong.

Multiple choice

StringBuffer s = new StringBuffer(“Welcome To Java”); s.delete(8,12);

What will be the output of the given code segment?

  1. Welcome ava

  2. Welcome va

  3. Welcomeava

  4. Compiler error : delete cannot be used with StringBuffer

  5. Runtime error
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct answer. delete(int start , int end) method deletes the characters from the start index until  the end -1 index. So, the welcome to java will delete the characters from 8 to 11 characters. Therefore, the resulting string remains “ Welcome ava”. The index starts from 0.

Multiple choice

String s = “Welcome To Java” s.substring(4, 4 );

What will be the answer of the given code?

  1. o

  2. c

  3. Empty string

  4. Compile time error

  5. Runtime error
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct answer. Substring method takes two parameters (beginIndex,EndIndex).Substring( int Begin , int End). It returns the string from begin to end – 1. But if the begin index is equal to the end index then an empty String with length 0 will be returned. So here substring(4,4) will return an empty string of length 0. So this is the correct answer.

Multiple choice

String s = “Welcome To Java”; s.length(); s.charAt(9);

What will be the output of the given code?

  1. s.length() = 14s.charAt(9) = T

  2. s.length() = 15s.charAt(9) = o

  3. s.length() = 15s.charAt(9) = T

  4. s.length() = 14s.charAt(9) = o

  5. Compiler error
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct answer. Length() function returns the number of characters in the string. The number of characters in the given string is 15. So length() will return 15.charAt() function return the character at the given index in the parameter. Remember that the index count starts at 0. So charAt(0) is W. Counting in this way we reach charAt(9) is o. So this is the correct answer.