Difference between parameter and arguments in C

The terms "arguments" and "parameters" are often used in the C programming, and they refer to different aspects of how functions work. Arguments are the actual values that are passed to a function when it is called. Parameters are the placeholders in the function definition that receive the arguments. When a function is called, the arguments are passed to the parameters in the order that they are listed in the function call.


Parameters are variables that are declared in the function's declaration or definition. They act as placeholders for values that the function expects to receive when it is called. Parameters are part of the function's signature and are used to define the function's input requirements.

return_type function_name(parameter_type parameter_name) { // Function body }

Parameters define the interface of the function, indicating what type of data it expects and how that data will be used within the function's logic.

void printMessage(char message[]) { printf("%s\n", message); }

In this example, message is a parameter of the printMessage function, and it expects a character array as input.


Arguments are the actual values or expressions provided to a function when it is called. They correspond to the parameters of the function and supply specific data for the function to work on.

function_name(argument1, argument2, ...);

Arguments supply concrete data to the function, allowing it to perform its tasks with specific values. They can be constants, variables, expressions, or even the results of other function calls.

char greeting[] = "Hello, world!"; printMessage(greeting);

In this example, greeting is an argument supplied to the printMessage function, matching the message parameter declared in the function's definition.


Parameters are variables declared in a function's definition that define the function's input requirements and serve as placeholders for data. Arguments, on the other hand, are the actual values or expressions provided to the function during its invocation, matching the parameters' order and data types. Parameters define the function's interface, while arguments supply specific data for the function to work with during its execution.