# Extra Clang Tools 18.1.8 documentation

## clang-tidy - google-objc-global-variable-declaration

# google-objc-global-variable-declaration

Finds global variable declarations in Objective-C files that do not follow the pattern of variable names in Google’s Objective-C Style Guide.

The corresponding style guide rule: https://google.github.io/styleguide/objcguide.html#variable-names

All the global variables should follow the pattern of `g[A-Z].*` (variables) or `k[A-Z].*` (constants). The check will suggest a variable name that follows the pattern if it can be inferred from the original name.

For code:

    static NSString* myString = @"hello";

The fix will be:

    static NSString* gMyString = @"hello";

Another example of constant:

    static NSString* const myConstString = @"hello";

The fix will be:

    static NSString* const kMyConstString = @"hello";

However for code that prefixed with non-alphabetical characters like:

    static NSString* __anotherString = @"world";

The check will give a warning message but will not be able to suggest a fix. The user needs to fix it on their own.