How Functions Work In C Language

Functions in C work by breaking up a program into smaller, more manageable pieces. When a function is called, the program execution jumps to the beginning of the function's code, where it performs the task that the function is designed to do. Once the task is complete, the program execution jumps back to the point where the function was called, and the program continues to execute from there.

When a function is called, it can take zero or more arguments, which are passed to the function by the calling code. These arguments are used by the function to perform its task. The function can also return a value or not, this value can be used by the calling code.

Functions use a stack data structure to manage the program execution flow. When a function is called, the current state of the program, including the values of any local variables, is saved on the stack. This is known as a "stack frame." Once the function is finished, the stack frame is popped off the stack, and the program execution resumes from where it left off.

Functions are also used to encapsulate complex logic, data and operations and hiding the implementation details behind the function, this way the calling code only have to know the function signature and not the internal details of it.

It is important to note that global variables are shared among all the functions in the program and can be accessed and modified by any function. However, local variables are only visible and accessible within the function in which they are defined, and they are created and destroyed when the function is called and returned respectively.