parameterName

Parameter name, often simply called a parameter, is an identifier used to refer to a value passed to a function, method, or procedure. It acts as a local variable inside the called code, receiving the corresponding argument value when the function is invoked. The parameter name is typically declared in the function's signature and used within the body.

When the function is called, the actual arguments are bound to the parameter names in order. This binding lasts for the duration of the call. For example, in Python, a function defined as def add(a, b): return a + b uses a and b as parameter names; calling add(3, 5) binds a to 3 and b to 5.

Naming: Parameter names should be descriptive and follow the conventions of the language. Clear names improve readability and generate better API documentation. In some languages, parameter names can be optional in declarations but are still used in the function body, and in others, named or keyword parameters allow arguments to be passed by name rather than by position.

Special cases: functions can have default parameter values, variadic parameters, or keyword-only parameters. Such features influence how callers provide values, but the parameter names remain the identifiers used inside the function to refer to the supplied values.

In software design, well-chosen parameter names support maintainability, debugging, and tooling such as IntelliSense or type hints. Poorly chosen names can confuse users of an API and increase the likelihood of incorrect arguments being supplied.