Member Avatar for skprasat

printf("\nThe Result is : %s %s %s %s %s %s %s %s\n",var[0],var[1],var[2],var[3],var[4],var[5],var[6],var[7]);

while executing this i get correct result upto var[4]....
and for var[5] and var[6] im geting some garbage valuess, then for var[7] im getg my result...
whats wrong in my code.....

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  • Latest Post Latest Post by axyelp

Dani AI

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The pattern — correct output for some indices, garbage for others, then a correct value again — points to undefined behaviour in how var is declared or filled, not to printf itself. 's loop suggestion is a good simplification for printing, and / were right to zero in on the declaration; 's request for the declaration is exactly the missing detail needed to diagnose this. Intermittent garbage usually means a bad pointer, a missing NUL terminator, or a memory overwrite that occasionally leaves one index looking valid.

Common safe declarations/uses to compare against the OP's unknown var:

/* fixed-size 2D array: each element has room for the NUL */
char var[8][32] = { "one", "two", /* ... */ };

/* array of pointers to string literals (read-only) */
const char *var[8] = { "one", "two", NULL, /* ... */ };

/* pointers with dynamic allocation (remember +1 for NUL) */
char *var[8] = {0};
/* var[5] = malloc(len + 1); snprintf(var[5], len+1, "%s", source); */

Practical troubleshooting checklist (in order): enable compiler warnings (-Wall -Wextra -Wformat), build with AddressSanitizer (-fsanitize=address) or run under Valgrind to catch overruns/use-after-free, and inspect pointers/lengths at runtime (print pointer values with %p and lengths with strlen) to see which elements are NULL, dangling, or non-terminated. Also verify every element you pass to %s is a valid char* pointing to a NUL-terminated buffer — a mismatched type in a variadic call invokes undefined behaviour (see printf argument rules).

Authoritative references: see the C printf specification and argument requirements at and the general discussion of undefined behaviour in C at . For memory-debugging tools, see Valgrind.

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Member Avatar for tksrules

Hi,
Think there's a problem with var[] array.mention details

Member Avatar for Ancient Dragon

wouldn't it have been a lot simpler to have coded it with a loop

int i;
printf(\nThe Result is : ");
for(i = 0; i < 7; i++)
   printf("%s ", var[i]);

>>whats wrong in my code.....
how did you declare and initialize array var ? Most likely the problem is uninitialized data.

Member Avatar for axyelp

ummmm....
how can you giv print to a single variable var with %s specifier???

your problem shouldn't be in the code but the definition of var[]!

Member Avatar for Ancient Dragon

ummmm....
how can you giv print to a single variable var with %s specifier???

Are you referring to the code I posted? I'm assuming var is an array of character arrays. It works because I used a loop that starts the variable i at 0 and increments it by one on each loop iteration. If you don't know about loops yet then you should read up on them.

Member Avatar for Prabakar

ummmm....
how can you giv print to a single variable var with %s specifier???

your problem shouldn't be in the code but the definition of var[]!

We don't know how it is declared, do we? It might be a 2D array or an array of Pointers or may be even vectors, the op should give more details if he/she wants a good answer

commented: Yeah, that and many other possible horrors +28
Member Avatar for axyelp

Are you referring to the code I posted? I'm assuming var is an array of character arrays. It works because I used a loop that starts the variable i at 0 and increments it by one on each loop iteration. If you don't know about loops yet then you should read up on them.

i meant to reply to op's post!
he should hav posted the definition of the the array for better understanding of the problem!

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