javascript remove empty slots in array console

You can convert an array to a string, which preserves commas: var myArray = Here we use the square bracket notation to set a new value for the fifth item in the array, which changed from “it’s over” to “the fat lady sings”. To change the value of an array item: var myArray = The number in square brackets is the index (or position) of the item you want to read or access.įor beginners: Remember that indexes start at zero. To read the value of an item in an array, you can do this: var myArray = Īlthough that is possible, it’s limited in usefulness, because the two new values are “undefined”, even though the length is now 7 instead of 5.

Interestingly, you can also redefine the size of the array using length: var myArray = Ĭonsole.log(myArray) // Īs shown above, after defining a 5-item array, we then set the length to “3”, which removes the final two items.Ĭonversely, you can add items using the length property: var myArray = To find out how many items are in an array, or how long an array is, you can use the length property: var myArray = But myArray2 is an array, so it returns true. Since myArray is not an array, Array.isArray() returns false. Var myArray2 = Ĭonsole.log(Array.isArray(myArray)) // falseĬonsole.log(Array.isArray(myArray2)) // true To find out if an object is a valid array, you can use Array.isArray(): var myArray = 'Misnomer' You can also do this with the array literal notation: var myArray = The following creates an array with 30 empty slots, each holding a value of undefined: var myArray = new Array(30) Īnd you can create an array with items already defined: var myArray = new Array('apples', 'oranges', 'pears', 'watermelons') You can also create an array with a set amount of “slots” in the array. The second (which is the recommended way to do this) is an array literal. The first of those is an array constructor. To create an array you can do one of the following: var myArray = new Array()

As usual, I’ll do my best to keep it simple and accurate, but if I’ve erred or if you think I’ve omitted anything important, please comment. Back in July I wrote a post called JavaScript String Methods Reference, outlining many of the ways strings can be manipulated in JavaScript.Īnother area where JavaScript has a number of different methods available for use is Array manipulation, which I’ll cover in this JavaScript array methods reference.

Javascript remove empty slots in array console