Why is the loop getting executed one time in the following code?

Question

int x;
int main(){
for(;x>=0;--x){cout<<"a";}
return 0;
}

If the value given to x was 0 then the loop would have been executed once but there is no value given to x then how come the loop is running and there is no error!
can someone please explain this?

Answer 1

In your example, 'x' is a global variable and has a static storage duration. Static variables are initialized to 0 by default. Had 'x' been a local variable it would contain garbage values.

Answer 2

As it gets executed for first time the value of x gets decremented and becomes -1 which doesn't satisfy the given condition of x>=0. So the loop gets executed only once.

Answer 3

try printing just x without the loop am sure x will be 0

Answer 4

Rishu Kumar that tells you the value of x is not a garbage value

Answer 5

x is from 0 to -1 = 1 iteration (for x=0) 🤔

Answer 6

since x is an external or globlal scope variable

default value of global variable is 0

Moreover it can be used any where and any no of times till end of the program

In loop 0>=0 is true 1 time loop is executed

next -1>=0 is false the control will come out from loop

that is the reason the mentioned loop will be executed only once

Answer 7

*Asterisk* yes it came out to be zero but isn't when a new variable is declared then initially it has some garbage value.

Answer 8

x is a global variable and has its default value as 0