C questions in placement tests and university exams are rarely about syntax alone. Most of what you will find here is output prediction, pointer arithmetic, arrays and strings, structures and unions, storage classes, recursion, and file handling. The explanations walk through memory behaviour step by step, which is usually where the confusion sits rather than in the code itself.
What is the behavior of this code? int i = 0; while(1) { i++; if(i > 5) break; }
Answer: B
while(1) creates an infinite loop. i increments until i > 5 (i becomes 6), then break exits. Loop runs 6 iterations.
Q.122Medium
Consider the code: int x = 5; if(x > 3) if(x > 10) printf("A"); else printf("B"); Which statement best describes the output?
Answer: B
The else binds to the nearest if statement (inner if). Since x=5 is not > 10, the inner condition fails and else executes, printing 'B'.
Q.123Medium
What does the following code segment accomplish? int i = 0; while(i < 5) { if(i == 2) { i++; continue; } printf("%d ", i); i++; }
Answer: B
When i==2, continue skips printf but still increments i. So 2 is not printed. Output: 0 1 3 4
Q.124Medium
Which of the following is a valid use of the switch statement in C?
Answer: C
Switch works with integral types only. Multiple case labels before statements (fall-through) is valid. Strings and floats are not allowed.
Q.125Medium
Analyze: What is printed by this code? for(int i = 1; i <= 3; i++) { for(int j = 1; j <= i; j++) { printf("%d", i); } printf(" "); }
Answer: D
Outer loop: i=1,2,3. Inner loop repeats i times. When i=1: print '1' once. i=2: print '2' twice. i=3: print '3' thrice. Each iteration separated by space.
Q.126Medium
What happens when you use break in a nested loop structure?
Answer: B
break statement exits only the innermost loop it's in. To break outer loop, you need additional logic or goto statement.
Q.127Medium
Consider the code: int x = 0; while(1) { if(++x > 3) break; printf("%d ", x); } What is the output?
Answer: B
Pre-increment ++x happens first. When x becomes 4, condition is true and loop breaks. Values printed: x=1,2,3 (before x reaches 4).
Q.128Medium
What is the key distinction between if-else and switch statements in terms of evaluation?
Answer: B
switch typically uses jump tables for efficient multi-way branching with integral values, while if-else evaluates boolean expressions sequentially.
Q.129Medium
What does the following code segment do? int i = 0; do { printf("%d ", i); } while(++i < 3);
Answer: A
do-while executes body first (prints 0), then checks ++i < 3. Loop continues for i=1,2. When i=3, condition fails. Output: 0 1 2
Q.130Medium
Consider: switch(x) { case 1: case 2: case 3: printf("A"); break; default: printf("B"); } What advantage does stacking cases provide?
Answer: B
Stacking cases (without break between them) allows multiple values to execute the same code block, reducing redundancy.
Q.131Medium
What does continue do in a for loop with multiple statements in body?
Answer: A
continue skips all remaining statements in the current loop iteration and jumps to the increment/condition check for the next iteration.
Q.132Medium
What is the output of the following code? int x = 5; if(x > 3) if(x < 10) printf("Pass"); else printf("Fail");
Answer: A
The inner if condition (x < 10) is true, so 'Pass' is printed. The else is associated with the inner if, not the outer one.
Q.133Medium
What is the output? int x = 10; while(x-- > 5) { printf("%d ", x); }
Answer: C
x-- returns the value before decrementing. Loop runs while value > 5: prints 9,8,7,6 (when x becomes 5, condition fails).
Q.134Medium
Which of the following statements about switch case is TRUE?
Answer: C
Without break, execution falls through to the next case. Default can be anywhere, and modern C allows switch with other types.
Q.135Medium
What will this code output? for(int i = 1; i <= 3; i++) { for(int j = 1; j <= i; j++) { printf("%d", j); } printf("\n"); }
Answer: A
Nested loop: outer loop runs 3 times, inner loop runs i times. Prints 1, then 12, then 123 on separate lines.
Q.136Medium
How many times will the loop execute? int i = 0; while(i++ < 5) { printf("%d ", i); }
Answer: B
i++ returns value before incrementing. Condition checks: 0<5(T), 1<5(T), 2<5(T), 3<5(T), 4<5(T), 5<5(F). Loop runs 5 times.
Q.137Medium
What will be the output of this code? int n = 5; switch(n) { case 4: printf("Four"); case 5: printf("Five"); case 6: printf("Six"); break; default: printf("Other"); }
Answer: B
n=5 matches case 5. Without break, it falls through to case 6 before encountering break. Prints 'FiveSix'.
Q.138Medium
Which control structure would be most efficient to validate if a number is within one of several specific values?
Answer: C
switch statement is optimized for multiple discrete value checks and is more readable than chained if-else statements.
Q.139Medium
In C programming, what is the difference between break in a loop and break in a switch statement?
Answer: C
Both break statements exit their immediate enclosing structure. In loops, break exits the loop; in switch, break exits the switch block.
Q.140Medium
What is the output of this code? char ch = 'B'; switch(ch) { case 'A': case 'B': case 'C': printf("Vowel"); break; default: printf("Consonant"); }
Answer: A
ch='B' matches case 'B', which has no statements. Execution falls through to case 'C' which has no statements, then prints 'Vowel' and breaks.
