What is the scope of a 'while' and 'for' loop?

Question

What is the scope of a while and for loop?

For example, if I declared an object within the loop, what is its behavior and why?

Answer 1

Check out this code

#include < stdio.h >

int i = 10;  
int main() {  

for(int i=0; i<3; i++) {  
    fprintf(stdout," for i = %d & upper i = %d\n",i,::i);

}  

while (i>3) {  
    int i = 30;  
    fprintf(stdout," while i = %d & upper i = %d\n",i,::i);  
    i++;  
    fprintf(stdout," while i = %d & upper i = %d\n",i,::i);  

}  

fprintf(stdout,"i = %d \n",i);  

}

In the code above, the global variable i is different from one which is controlling the for loop.

It will print

for i = 0 & upper i = 10
for i = 1 & upper i = 10
for i = 2 & upper i = 10

when while loop is executed - the variable i defined inside while is having local scope, where as the variable under (i > 3) follows the global variable, and doesn't refer to local scope.

Dipan.