Menu
What is the usage of global:: keyword in C#? When must we use this keyword?
707
The C language does not have a global keyword. However, variables declared outside a function have "file scope," meaning they are visible within the file. Variables declared with file scope are visible between their declaration and the end of the compilation unit ( .
Use of the Global Variable in C The global variables get defined outside any function- usually at the very top of a program. After this, the variables hold their actual values throughout the lifetime of that program, and one can access them inside any function that gets defined for that program.
A global keyword is a keyword that allows a user to modify a variable outside of the current scope. It is used to create global variables in python from a non-global scope i.e inside a function. Global keyword is used inside a function only when we want to do assignments or when we want to change a variable.
The C compiler recognizes a variable as global, as opposed to local, because its declaration is located outside the scope of any of the functions making up the program. Of course, a global variable can only be used in an executable statement after it has been declared.
Technically, global is not a keyword: it's a so-called "contextual keyword". These have special meaning only in a limited program context and can be used as identifiers outside that context.
global can and should be used whenever there's ambiguity or whenever a member is hidden. From here:
class TestApp { // Define a new class called 'System' to cause problems. public class System { } // Define a constant called 'Console' to cause more problems. const int Console = 7; const int number = 66; static void Main() { // Error Accesses TestApp.Console Console.WriteLine(number); // Error either System.Console.WriteLine(number); // This, however, is fine global::System.Console.WriteLine(number); } } Note, however, that global doesn't work when no namespace is specified for the type:
// See: no namespace here public static class System { public static void Main() { // "System" doesn't have a namespace, so this // will refer to this class! global::System.Console.WriteLine("Hello, world!"); } } If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
