Functions
Functions are just recipes. Generally speaking, a function is a code snippet (subprogram) that can be called by other code, by itself, or a variable that refers to the function.
When a function is called, arguments are passed to the function as input, and the function can optionally return an output.
Using a recipe analogy, this would be the basic concept of a function to make a salami sandwich…
// The steps
makeSalamiSandwich
Get one slice of bread.
Add salami.
Put a slice of bread on top.
// The function
function makeSalamiSandwich() {
Get one slice of bread;
Add salami;
Put a slice of bread on top;
}
// Call the function
makeSalamiSandwich();
Customizing Functions
- Parameters - the names of the arguments to be passed to the function.
Using the same recipe analogy from above, we will adjust the steps to accomodate for customizing the Salami sandwich:
// The steps
makeSandwichWith ____
Get one slice of bread.
Add ____.
Put a slice of bread on top.
// The function
function makeSandwichWith(filling) {
Get one slice of bread;
Add filling;
Put a slice of bread on top;
}
// Call the function
makeSandwichWith(salami);
Conceptual example of customizing a function:
> function sayHiTo(person) {
console.log(`Hi, ${person}`);
}
// Set the person variable to John
> sayHiTo('John');
Hi, John