Output of C Programs | Set 14
Predict the output of below C programs.
Question 1
C
#include<stdio.h>int main(){ int a; char *x; x = (char *) &a; a = 512; x[0] = 1; x[1] = 2; printf("%d\n",a); getchar(); return 0;} |
Answer: The output is dependent on endianness of a machine. Output is 513 in a little endian machine and 258 in a big endian machine.
Let integers are stored using 16 bits. In a little endian machine, when we do x[0] = 1 and x[1] = 2, the number a is changed to 00000001 00000010 which is representation of 513 in a little endian machine. The output would be same for 32 bit numbers also.
In a big endian machine, when we do x[0] = 1 and x[1] = 2, the number is changed to 00000001 00000010 which is representation of 258 in a big endian machine.
Question 2
C
int main(){ int f = 0, g = 1; int i; for(i = 0; i < 15; i++) { printf("%d \n", f); f = f + g; g = f - g; } getchar(); return 0;} |
Answer: The function prints first 15 Fibonacci Numbers.
Question 3
Explain functionality of following function.
C
int func(int i){ if(i%2) return (i++); else return func(func(i-1));} |
Answer: If n is odd then returns n, else returns (n-1). So if n is 12 then we get 11 and if n is 11 then we get 11.
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