This content originally appeared on Go Make Things and was authored by Go Make Things
Within a function, you can use the arguments variable to get an array-like list of all of the arguments passed into the function.
You don’t need to define it ahead of time. It’s a native JavaScript object.
function add (num1, num2) {
// logs [num1, num2] (with their values)
console.log(arguments);
// logs the value of `num1`
console.log(arguments[0]);
// logs the value of `num2`
console.log(arguments[1]);
// ...
}
This is particularly useful if you would rather allow an unlimited number of arguments to be passed in to your function.
Let’s say you wanted to be able to pass an unlimited amount of numbers into add() and add them together. The arguments variable is perfect for this!
Remember, arguments is array-like but not actually an array. To use array methods like Array.forEach() with it, you need to convert it to an array with the Array.from() method.
function add () {
// Set a starting total
let total = 0;
// Add each number to the total
Array.from(arguments).forEach(function (num) {
total += num;
});
// Return to the total
return total;
}
In the example above, we’re defining a default variable total with a value 0. We use Array.from() to convert arguments to an array, and an Array.forEach() loop to iterate over each argument and add it to the total. Then we return the total.
If someone passes in no arguments, it returns 0. Otherwise, they can add one or more numbers together.
// returns 0
add();
// returns 4
add(4);
// returns 36
add(4, 2, 11, 19);
This content originally appeared on Go Make Things and was authored by Go Make Things
Go Make Things | Sciencx (2021-03-19T14:30:00+00:00) The arguments object in JavaScript functions. Retrieved from https://www.scien.cx/2021/03/19/the-arguments-object-in-javascript-functions/
Please log in to upload a file.
There are no updates yet.
Click the Upload button above to add an update.