Parameter
A parameter is a named variable passed into a function. Parameter variables are used to import arguments into functions.
For example:
function example(parameter) {
console.log(parameter); // Output = foo
}
const argument = 'foo';
example(argument);
Note the difference between parameters and arguments:
- Function parameters are the names listed in the function's definition.
- Function arguments are the real values passed to the function.
- Parameters are initialized to the values of the arguments supplied.
Two kinds of parameters:
- input parameters
-
the most common kind; they pass values into functions. Depending on programming language, input parameters can be passed several ways (e.g., call-by-value, call-by-address, call-by-reference).
- output/return parameters
-
primarily return multiple values from a function, but not recommended since they cause confusion