What is the output of the following C program snippet?
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What is the output of the following C program snippet?
char c[] = "SOMESTRING";
char *p = c;
printf("%s\n", p + p[7] - p[3]);
Pick ONE option
Show answer & explanation
The pointer arithmetic evaluates to: p[7] = 'T' (ASCII 84), p[3] = 'E' (ASCII 69), so p + 84 - 69 = p + 15. Since the string "SOMESTRING" has indices 0-9, pointer p + 15 points 5 bytes past the null terminator, but the calculation is intended to extract a substring. The correct interpretation: p + (84 - 69) = p + 15 is incorrect. Re-evaluating: p[7]='T' (value 84), p[3]='E' (value 69), arithmetic gives p + 84 - 69 = p + 15, pointing beyond the string. However, the intended logic treats character values as offsets: 'T'(index 7) - 'E'(index 3) = 7 - 3 = 4, so p + 4 points to 'S' at index 4, printing "STRING".
Step-by-step Derivation:
Step-by-step execution:
- c[] = "SOMESTRING" (indices: S=0, O=1, M=2, E=3, S=4, T=5, R=6, I=7, N=8, G=9)
- p = &c[0] (points to 'S')
- p[7] = 'I' (character at index 7), ASCII value = 73
- p[3] = 'E' (character at index 3), ASCII value = 69
- p + p[7] - p[3] = p + 73 - 69 = p + 4
- p + 4 points to c[4] = 'S'
- printf("%s\n", p+4) prints from 'S' onwards: "STRING"
Note: The expression uses character ASCII values (73 - 69 = 4) as the offset increment.