📘 Lesson · Lesson 59

Storage Classes

What are Storage Classes?

💡 Note

Storage classes define a variable's scope, lifetime and default value.

Class	Meaning
auto	default for local variables
register	suggest storing in CPU register (fast)
static	keeps value between function calls
extern	variable defined in another file

void counter() {
    static int count = 0;   // keeps value
    count++;
    printf("%d ", count);
}
counter(); counter(); counter();   // 1 2 3

Output:
1 2 3

auto = local default; register = fast; static = persists between calls; extern = defined elsewhere.

💡 Note

Storage classes variable का scope, lifetime और default value तय करते हैं।

Class	मतलब
auto	local variables का default
register	CPU register में रखने का सुझाव (तेज़)
static	function calls के बीच value रखता है
extern	दूसरी file में defined variable

void counter() {
    static int count = 0;   // value रखता है
    count++;
    printf("%d ", count);
}
counter(); counter(); counter();   // 1 2 3

Output:
1 2 3

auto = local default; register = तेज़; static = calls के बीच रहता; extern = कहीं और defined।