What is the purpose of the “static” keyword in the C language?

In the C language, the static keyword serves the following purposes:

1. Scope Limitation: When the static keyword is used with global variables or functions, it restricts their scope to only be visible in the source file where they are defined, and cannot be accessed in other source files. This helps to prevent naming conflicts for global variables and functions.
2. Prolonging lifespan: When the static keyword is used for local variables, it extends the variable’s lifespan, allowing it to persist after the function call ends. This means the value of the variable remains unchanged between different function calls.
3. Maintain the persistence of variables: when the static keyword is used for a local variable, it makes the variable a static variable, meaning it will only be initialized once and will maintain its value between function calls. This allows static variables to share data between function calls.
4. In functions, saving state: When the static keyword is used for local variables, it can be used to preserve the value of the static variable between function calls. The value of the static variable remains the same as it was at the end of the last function call each time the function is called.

In general, the static keyword can be used to limit scope, prolong the lifespan of a variable, maintain variable persistence, and save state in a function.