Javascript array splice vs slice how to#

log (str ) // // not modified splice(startIndex, number, items) It takes a start index and an end index (excluded) and slices those array items and gives back to you.

Javascript array splice vs slice how to#

In this article, I will walk you through how to use the slice () and splice () array methods using code examples. So let's sort this out: slice(startIndex, endIndex) When you are first learning JavaScript, it might be difficult to know the difference between the slice () and splice () array methods. Because of that, it pulls the items out of the original array and hence modifies it, and thus, slice does not pull items out of the original array.Īlso, because it pulls items, it can also push items into the array. Notice that splice has an extra p in the method name. If start > array.length, nothing is extracted.

If start < -array.length or start is omitted, 0 is used. Negative index counts back from the end of the array if start < 0, start + array.length is used. Here is a mnemonic technique that you can use so that there is no need for another Google search in your entire life while working on JS arrays. Syntax js slice() slice(start) slice(start, end) Parameters start Optional Zero-based index at which to start extraction, converted to an integer. log (str ) // Ĭhanges the contents of the array by removing/replacing existing items let str = console. Returns a section of the original string without changing the original string let str = console. To the uninitiated, Javascript provides us with two methods on the Array prototype which look ever so similar but function worlds apart. You know there exists a slice as well as a splice method on the Array prototype but still, open google, type javascript array slice, then javascript array splice, compare them and then make your decision, every single time!ĭo you wish to break this loop and become a JS array ninja who just knows which one of the two is to be used in which case? Then follow along.

If you are like me and have spent most of your recent years coding in Javascript you definitely have come across this conundrum: There is this array and you want to do an operation on it to get a transformed version.