Computer Knowledge

Programming Output Evaluation

1,953 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 technology programming languages
  1. Compile error : Integer can't add

  2. newyork ca texas 11

  3. newyork ca texas

  4. newyork ca

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

To understand the output of the given code, it is important to know the concept of Queue in Java.

A Queue is a data structure that follows the First-In-First-Out (FIFO) principle. In a Queue, elements are added from the rear and removed from the front. The methods used to add elements to the Queue are 'add' and 'offer', whereas 'poll' and 'remove' are the methods used to remove elements from the Queue.

Now let's go through the code and analyze the output.

The code creates a Queue of Strings named 'q' and adds three Strings to it: "newyork", "ca", and "texas". Then the method 'show(q)' is called, and a new Integer object 11 is added to the Queue 'q' inside the 'show' method. Finally, the elements of the Queue are printed using the 'poll' method.

Since the Queue 'q' has been defined as a Queue of Strings, adding an Integer object to the Queue will result in a compile-time error. Therefore, option A is incorrect.

The 'poll' method removes and returns the head of the Queue. So, the output will be the elements of the Queue in the order they were added. Thus, option C is incorrect because it does not include the added Integer object.

Therefore, the correct answer is:

The Answer is: B. newyork ca texas 11

Multiple choice technology
  1. The program does not compile as j is not initialized

  2. The program compiles but does not run

  3. The program compiles and runs but does not print anything

  4. prints some value

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Local variable 'j' is used without being initialized - in Java, local variables must be explicitly initialized before use. The 'j++' operation in the do-while tries to increment an uninitialized variable, causing a compile-time error. This is different from instance variables which get default values.

Multiple choice technology java
  1. 50

  2. ‘\u0000'

  3. cannot be determined

  4. always null until a value is

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

To answer this question, you need to understand how arrays work in Java. Specifically, the behavior of character arrays when they are initialized.

In Java, when you create an array, all elements in the array are automatically initialized to their default values. For the char data type, the default value is the null character, represented as '\u0000'.

Let's go through each option to understand why it is correct or incorrect:

Option A) 50 - This option is incorrect. When an array of char type is created in Java, its elements are not automatically initialized to their indices. Therefore, c[50] is not equal to 50.

Option B) ‘\u0000' - This option is correct. As mentioned above, when a char array is created in Java, its elements are automatically initialized to the null character, '\u0000'. Therefore, c[50] is equal to '\u0000'.

Option C) cannot be determined - This option is incorrect. In Java, the behavior of array initialization is well-defined. For a char array, all elements are automatically initialized to '\u0000'. Therefore, the value of c[50] can be determined.

Option D) always null until a value is - This option is incorrect. In the context of Java, "null" usually refers to a reference that does not point to any object. But for primitive types, such as char, the concept of "null" does not apply. The default value for a char is '\u0000', not "null".

The correct answer is B) ‘\u0000'. This option is correct because in Java, when a char array is initialized, all of its elements are automatically set to the null character, '\u0000'.

Multiple choice technology
  1. It will not compile because the

  2. "Equal A" is the only thing that is printed

  3. "Equal B" is the only thing that is printed

  4. Both "Equal A" and

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The == operator compares object references, not content. Since new String("Computer") creates a distinct String object in memory, s == "Computer" is false (they point to different objects). The equals() method compares actual string values, so s.equals("Computer") is true, printing "Equal B".

Multiple choice technology
  1. (5, 3) (5, 3) (5, 3)

  2. (5, 3) (3, 5) (5, 3)

  3. (5, 3) (3, 5) (3, 5)

  4. (3, 3) (3, 5) (3, 5)

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Java passes primitive parameters by value, so switchCoords receives copies of x and y (values 5 and 3). Inside switchCoords, the swap changes only these local copies: temp=5, x becomes 3, y becomes 5, printing "(3, 5)". After the method returns, myMethod's original x and y remain unchanged at 5 and 3, so it prints "(5, 3)".

Multiple choice technology
  1. Returns the index of the highest

  2. Returns true/false if there are any elements that repeat in the array

  3. Returns how many even numbers are in the array

  4. Returns the highest element in the array

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ternary operator x = x < arr[i] ? arr[i] : x compares current x with each array element. If arr[i] is larger than x, x becomes arr[i]; otherwise x stays the same. After iterating through all elements, x holds the maximum value found in the array.

Multiple choice technology
  1. 1.// Looks like a comment

  2. 2.The statement results in a compilation error

  3. 3.Looks like a comment

  4. 4.No output is displayed

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In Java, text inside double quotes is always a String literal, regardless of its content. The compiler does not treat // inside quotes as comments. The statement prints the literal string // Looks like a comment. There is no compilation error because the syntax is valid.

Multiple choice technology
  1. Compile error

  2. amitPoddar o

  3. amitPoddar i

  4. amit i

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Strings in Java are immutable - s1.concat() returns a new String but doesn't modify s1. s1 remains amit. s2 becomes aiit after replacing m with i. s1+s2 is amitaiit, and charAt(5) is i (0-indexed: a=0, m=1, i=2, t=3, a=4, i=5). So output is amit i.

Multiple choice technology programming languages
  1. It will not compile.

  2. It will print out: i=9.

  3. It will print out: i=10.

  4. It will loop indefinitely

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The function increment accepts its parameter by value, which means it only increments a local copy of the variable inside the function. Because the global loop variable i in the main function is never updated, the loop runs indefinitely.

Multiple choice technology programming languages
  1. efg

  2. cdefg

  3. fg

  4. None of the above

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To solve this question, the user needs to understand the concept of pointers in C programming. In this case, ptr is a pointer variable that points to the first character of the myString array. The statement ptr += 5 increments the pointer by 5, so that it now points to the sixth character in the array.

Option A is incorrect because ptr is pointing to the sixth character in the array, not the third.

Option B is incorrect because ptr is pointing to the sixth character in the array, not the first.

Option C is correct because ptr is pointing to the sixth character in the array, which is "f", and continues to the end of the string, "g". Therefore, the string that ptr points to is "fg".

Option D is incorrect because an answer was provided above.

Therefore, the answer is: C. fg

Multiple choice technology programming languages
  1. y = LLO

  2. y = LO

  3. y = ELLO

  4. y = HELLO

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The function increments the pointer by 3 characters. 'HELLO' + 3 points to 'LO' (the 4th character, index 3). Pointer arithmetic moves forward by 3 positions, so ptr goes from 'H' to 'L'. printf then prints 'LO'. Option B is correct. Options A ('LLO') would be +2, C ('ELLO') would be +1, D would be no pointer change.

Multiple choice technology mainframe
  1. 4

  2. 5

  3. 6

  4. 1

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The PERFORM VARYING loop iterates with C starting at 1 and incrementing by 1 until C equals 6. Since the condition UNTIL C = 6 is checked before each iteration, the loop runs for C = 1, 2, 3, 4, 5 (5 iterations), and stops when C becomes 6. Therefore RESULT = 5.

Multiple choice technology programming languages
  1. x: 6 y: 16

  2. x: 10 y: 26

  3. x: 10 y: 15

  4. x: 6 y: 15

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The postfix increment operator x++ evaluates to the current value of x (which is 5) before incrementing it to 6. Thus, y += 5 sets y to 15, and x is updated to 6, matching the correct output.

Multiple choice technology programming languages
  1. The class compiles and runs, but does not print anything

  2. The number 2 gets printed with AssertionError

  3. The number 3 gets printed with AssertionError

  4. compile error

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The code compiles and runs without printing anything because assertions are disabled by default in Java. The nested loops iterate i=2,3 and j=2,3, checking if i