Redeclaration of global variable in C
Consider the below two programs:
// Program 1 int main() { int x; int x = 5; printf ( "%d" , x); return 0; } |
Output in C:
redeclaration of ‘x’ with no linkage
// Program 2 int x; int x = 5; int main() { printf ( "%d" , x); return 0; } |
Output in C:
5
In C, the first program fails in compilation, but second program works fine. In C++, both programs fail in compilation.
C allows a global variable to be declared again when first declaration doesn’t initialize the variable.
The below program fails in both C also as the global variable is initialized in first declaration itself.
int x = 5; int x = 10; int main() { printf ( "%d" , x); return 0; } |
Output:
error: redefinition of ‘x’
This article is contributed Abhay Rathi.