Computer Knowledge

Programming Fundamentals

2,611 Questions

Programming fundamentals form the core logic of software development and computer science. This includes variable declarations, pointer assignments, loop iterations, and exception handling. These technical topics are regularly tested in computer knowledge and IT officer competitive examinations.

Variables and arraysPointer assignmentsLoop iterationsException handling blocksCompile time errorsFunction references

Programming Fundamentals Questions

Multiple choice

Which of the following way of passing arguments to a procedure allows a special calling convention to be used that explicitly indicates the argument to be provided and the associated value?

  1. Positional Arguments

  2. Named Arguments

  3. Exit Sub

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This way of passing arguments to a procedure allows a special calling convention to be used that explicitly indicates the argument to be provided and the associated value

Multiple choice

Which of the following are true? I. A programming language which does not permit global variables of any kind and has no nesting of procedures/functions, but permits recursion can be implemented with static storage allocation II. Multi-level access link (or display) arrangement is needed to arrange activation records only if the programming language being implemented has nesting of procedures/functions III. Recursion in programming languages cannot be implemented with dynamic storage allocation IV. Nesting procedures/functions and recursion require a dynamic heap allocation scheme and cannot be implemented with a stack-based allocation scheme for activation records V. Programming languages which permit a function to return a function as its result cannot be implemented with a stack-based storage allocation scheme for activation records

  1. II and V only

  2. I, III and IV only

  3. I, II and V only

  4. II, III and V only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Multiple choice

The enter_CS() and leave_CS() functions to implement critical section of a process are realized using test-and-set instruction as follows:

void enter_CS(X)
{
    while(test-and-set(X));
}

void leave_CS(X)
{
    X = 0;
}

In the above solution, X is a memory location associated with the CS and is initialized to 0. Now consider the following statements: I. The above solution to CS problem is deadlock-free. II. The solution is starvation free. III. The processes enter CS in FIFO order. IV More than one process can enter CS at the same time. Which of the above statements is/are TRUE?

  1. Only I

  2. Both I and II

  3. Both II and III

  4. Only IV
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Multiple choice

The following C function takes a simply-linked list as input argument. It modifies the list by moving the last element to the front of the list and returns the modified list. Some part of the code is left blank.

typedef struct node {
  int value;
  struct node * next;
}Node;

Node * move_to_front(Node * head) {
    Node * p, * q;
    if ((head = = NULL: || (head - > next = = NULL)) return head; q = NULL; p = head;
      while (p - > next != NULL) {
        q = P;
        p = p - > next;
      }
      return head;
    }

Choose the correct alternative to replace the blank line.

  1. q = NULL; p->next = head; head = p;

  2. q->next = NULL; head = p; p->next = head;

  3. head = p; p->next = q; q->next = NULL;

  4. q->next = NULL; p->next = head; head = p;
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Multiple choice

The program below uses six temporary variables a, b, c, d, e, f.

a = 1
b = 10
c = 20
d = a + b
e = c + d
f = c + e
b = c + e
e = b + f
d = 5 + e
return d + f

Assuming that all operations take their operands from registers, what is the minimum number of registers needed to execute this program without spilling?

  1. 2

  2. 3

  3. 4

  4. 6
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is a register allocation problem using graph coloring principles. Tracking live variables: a=1 (a live), b=10 (a,b), c=20 (a,b,c), d=a+b (b,c,d) - a dead, e=c+d (c,d,e) - b dead, f=c+e (c,e,f) - d dead, b=c+e (b,c,e,f), e=b+f (b,e,f) - c dead, d=5+e (d,e,f) - b dead, return d+f (d,f). At the end, we need d and f alive simultaneously. Minimum registers needed = 3. We can allocate: R1=e (then f), R2=c (through multiple uses), R3=d (final). This satisfies all constraints with 3 registers. With only 2 registers, we'd need to spill a variable.