Runtime Environments and Storage Questions and Answers

Q: What will be the output of the following pseudo-code when parameters are passed by reference and dynamic scoping is assumed?a=3; void n(x) {x = x * a; print(x);} void m(y) {a = 1; a = y - a; n(a); print(a);} void main() {m(a);}

The keyed output is 4, 4.The pseudo-code has no declarations, so the key rests on reading the assignment a = 1 inside m as creating m's own local variable a (as an assignment does in many dynamically scoped languages). Under that reading:main calls m(a); y is a reference to the global a, which is 3.In m, a = 1 creates the local a; then a = y - a = 3 - 1 = 2.m calls n(a); x is a reference to m's local a. With dynamic scoping, the a inside n is the most recent active binding, m's local a, the same variable as x. So x = x * a = 2 * 2 = 4, and n prints 4.Back in m, print(a) prints the local a, now 4.If every a were the single global variable, the output would be 0, 0 (a = 1, then a = y - a = 1 - 1 = 0), which is not offered; the options therefore assume the local reading. Under it, both prints show the same variable after n has changed it, which is why the two printed values are equal, ruling out 6, 2 and 4, 2.

Q: In C runtime environment, which one of the following is stored in heap?

The item stored in the heap is a dynamically allocated array of integers created using malloc().In a C program the heap is the region managed by malloc(), calloc(), realloc() and free(). Memory obtained from malloc() stays allocated until it is freed, independent of function calls, which is exactly what the heap is for.A static variable declared inside a function lives in the static data segment (.data or .bss), not on the heap. An ordinary array declared inside a function is an automatic variable on the stack, and the return address of a function is pushed onto the stack as part of its activation record.

What will be the output of the following pseudo-code when parameters are passed by reference and dynamic scoping is assumed?

a=3;
void n(x) {x = x * a; print(x);}
void m(y) {a = 1; a = y - a; n(a); print(a);}
void main() {m(a);}

A.6, 2
B.6, 6
C.4, 2
D.4, 4

Exam Year(s)

GATE CS - 2016,

Answer: D

The keyed output is 4, 4.

The pseudo-code has no declarations, so the key rests on reading the assignment a = 1 inside m as creating m's own local variable a (as an assignment does in many dynamically scoped languages). Under that reading:

main calls m(a); y is a reference to the global a, which is 3.
In m, a = 1 creates the local a; then a = y - a = 3 - 1 = 2.
m calls n(a); x is a reference to m's local a. With dynamic scoping, the a inside n is the most recent active binding, m's local a, the same variable as x. So x = x * a = 2 * 2 = 4, and n prints 4.
Back in m, print(a) prints the local a, now 4.

If every a were the single global variable, the output would be 0, 0 (a = 1, then a = y - a = 1 - 1 = 0), which is not offered; the options therefore assume the local reading. Under it, both prints show the same variable after n has changed it, which is why the two printed values are equal, ruling out 6, 2 and 4, 2.

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In C runtime environment, which one of the following is stored in heap?

A.A static variable declared inside a function
B.An array of integers declared inside a function
C.A dynamically allocated array of integers created using malloc() function call
D.Return address of a function

Exam Year(s)

GATE CS - 2026,

Answer: C

The item stored in the heap is a dynamically allocated array of integers created using malloc().

In a C program the heap is the region managed by malloc(), calloc(), realloc() and free(). Memory obtained from malloc() stays allocated until it is freed, independent of function calls, which is exactly what the heap is for.

A static variable declared inside a function lives in the static data segment (.data or .bss), not on the heap. An ordinary array declared inside a function is an automatic variable on the stack, and the return address of a function is pushed onto the stack as part of its activation record.

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