+ 2

What is the use n application of Static variables in C?

3rd Mar 2019, 4:56 PM
Muhesh Kumar
2 odpowiedzi
+ 4
When you want a variable that is only initialized once for a function that is called multiple times.
5th Mar 2019, 1:34 PM
Sonic
Sonic - avatar
+ 2
Lets say that you have a function that gets executed every time an even triggers.. (ej. a 1s timer callback) If you want to increment a minute counter, you have to count how many times the function gets executed... This may be implemented with a global variable: int seconds = 0; // global for counting seconds int minutes = 0; void timer_callback(){ seconds++; if (seconds == 60) { seconds = 0; minutes++; } } int main(){ <some code> } If you want to make "seconds" local (because globals are evil :P ), but you need seconds to keep it's value -like a global do- you can declare as static (inside the function): int minutes = 0; void timer_callback(){ static int seconds = 0; // seconds is static seconds++; if (seconds == 60) { seconds = 0; minutes++; } } int main(){ <some code> } As "seconds" is static, is local to timer_callback() -so it's "invisible" to the rest of the program- but don't lose it's value when function ends... Note: It gets initialized (in this example to 0) ONLY the first time the function is called... Hope that this example helps you... :)
5th Mar 2019, 12:13 AM
unChabon
unChabon - avatar