Dylan: info, C example, comparison to local variables

2025-08-12T10:36:24Z

info, C example, comparison to local variables

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A '''global variable''' is a [[variable]] which is valid throughout the [[lifetime]] of the [[program]]'s execution.

By definition, it does '''not''' have a [[scope]].

== Example of a global variable in [[C]] ==
<syntaxhighlight lang="c" line="1">
#include <stdio.h>
int number = 6;

void printNumber() { // no parameters...
printf("%d", number); // ... but we can still access 'number'
}

int main() {
number = 12; // assign a new value to global variable 'number'
printNumber(); // prints '12'
}
</syntaxhighlight>

== Comparison to [[Local variable|local variables]] ==
[[Local variable|Local variables]] are '''only valid inside a specific [[scope]]'''.

Usually, this [[scope]] is a [[code block]], such as an [[if statement]] or [[subroutine]] ([[function]] or [[procedure]]).

'''Global''' [[Variable|variables]] on the other hand are not bound to a specific [[scope]] or [[code block]], but can instead be accessed anywhere in the [[program]].

Global variable - Revision history

Dylan: info, C example, comparison to local variables