Question

Possible Duplicate:
Why does printf print wrong values?

#include<stdio.h>

int main(int argc, const char *argv[]){
    float f1 = 125.2f;

    printf("\n [%f] [%d] [%g]",f1,f1,f1);
    printf("\n [%f] [%g] [%d]",f1,f1,f1);
    printf("\n [%g] [%f] [%d]",f1,f1,f1);
    printf("\n [%g] [%d] [%f]",f1,f1,f1);
    printf("\n [%d] [%g] [%f]",f1,f1,f1);
    printf("\n [%d] [%f] [%g]",f1,f1,f1);  
    getchar();
}  

I can see different output from each printf, though printing the same variable with same format identifier.

Answer 1

printf is not type safe so using a incorrect format descriptor results in Undefined Behavior.

An Undefined Behavior means that any observable behavior is possible because the code is not abiding the rules laid out by the standard.