garbage

int a=5; float b=3.5; printf("%d",b); printf("\n%f",a); Can anyone please tell me why this code is showing unexpected output (garbage\n3.5) Grijesh Chauhan Format string incorrect error, according to your declarations of a and b : printf("%d",b); <-- "b is float" Wrong! printf("\n%f",a); <-- "a is an int" Wrong! -- Undefined behavior should be: printf("%f",b); printf("\n%d",a); Q :- Why you getting that output? It's due to undefined behavior of your code: From INTERNATIONAL STANDARD ©ISO/IEC ISO/IEC 9899:201x 7.16.1 Variable argument list access macros (page 270) 7.16.1.1 The va_arg macro [...

This question already has an answer here: (Why) is using an uninitialized variable undefined behavior? 7 answers Possible Duplicate: Is uninitialized data behavior well specified? I tried the following code #include<stdio.h> void main() { int i; \ printf('%d',i); } The result gave garbage value in VC++, while same in tc was zero. What will be the correct value? Will an uninitialized variable by default have value of zero? or it will contain garbage value? Next is on the same #include<stdio.h> void main() { int i,j,num; j=(num>0?0:num*num); printf("\n%d",j); } What will be the output of the

If a function has a return type other than void , and the function does not return anything, then I guess the compiler returns a garbage value (possibly seen as an uninitialized value). It happens at compile time, so why shouldn't it throw an error? For example, int func1() { return; // error } int func2() { // does not return anything } The second func2 should throw an error, but it does not. Is there a reason for it? My thinking was such that, it can be seen as an uninitialized value, so if we need to throw an error in the second case, then we need to throw error, if an value is