length property - see how it still says length: 4?! Another reason to avoid using delete. What’s more confusing is delete doesn’t affect the Array’s. I included this for clarity, it’s always great to see and understand what side effects your operations have. You’ll notice from the console.log output above that it completely blows away the key. Let’s take an array with a few string values:Ĭonst drinks = const id = 2 delete drinks // Array(4) // 0: 'Cola' // 1: 'Lemonade' // 3: 'Water' // length: 4 // _proto_: Array(0) console. This could be removing or replacing “elements”, as array items are known. Splice is a mutable method that allows you to change the contents of an array. To remove an item from array via its index, we’ll first introduce the method and then investigate a better pattern using, a newer API. Without further ado, let’s first explore how to remove an item from an array in JavaScript by index and value. Each draw contains something unique! Arrays are virtual, so the size of the filing cabinet is up to you!īecause now you understand an array, you know how to work with one! Really, you can think of each index as a drawer in a filing cabinet. Ask for the index from your array and you’ll get back the item located at that index. With arrays this means when we need access to a value, whatever it may be (a primitive/object), it’s done via an “index lookup”. An index? Yes - 0, 1, 2, 3 and onwards! Array indexes start at zero. It is still an object, but the way that we “use” an array is by accessing properties on it that refer to an item in the array, via an index. The array object is special, it’s different. With that said, you now know how arrays are actually just objects - and objects have methods and properties. Both of these are inherited methods on the array object. The intention with this was to allow us to perform mutations and changes to our arrays with the nice utility functions “built-in”.Ī utility? Yes, for example () or (). For example when we declare a new array via, that array contains Array.prototype properties and methods that allow us to interact with our array.

Javascript array splice remove