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Array slice in javascript
Array slice in javascript










array slice in javascript

Use negative numbers to select from the end of an array. If omitted, all elements from the start position and to the end of the array will be selected.

array slice in javascript

An integer that specifies where to end the selection. Use negative numbers to select from the end of an array.Īrgument 2: Optional. An integer that specifies where to start the selection (The first element has an index of 0). The new item(s) to be added to the array.Īrgument 1: Required. And if not passed, all item(s) from provided index will be removed.Īrgument 3.n: Optional. If set to 0(zero), no items will be removed. Splice() method can take n number of arguments:Īrgument 2: Optional.

array slice in javascript

The splice() method changes the original array and slice() method doesn’t change the original array. The slice() method returns the selected element(s) in an array, as a new array object. The splice() method returns the removed items in an array. Returns: An array containing the extracted elements. If end is negative it is treated as "Math.max((array.length + begin),0)" as per spec (example provided below) effectively from the end of array. Last index for extraction but not including (default array.length). If begin is negative it is treated as "Math.max((array.length + begin), 0)" as per spec (example provided below) effectively from the end of array. Remove last element (start -> array.length+start = 3)Ĭonsole.log('Elements deleted:', array.splice(-1, 1), 'mutated array:', array) And you're equipped with a handy mnemonic, that splice compared to slice has an additional letter, 'p', which helps you remember that splice mutates and optionally adds or removes from the original ('Elements deleted:', array.splice(0, 1), 'mutated array:', array) You now know that slice makes a shallow copy of the original array, while splice mutates the original array and optionally adds or removes elements. ConclusionĪnd there we have it! This blog goes over the differences between slice and splice. And because splice can add and remove stuff to the original array, that means that it also mutates the original array. Because of the extra letter, I associate the additional letter to splice's use of adding or removing from the original array. splice has an extra letter, 'p', compared to slice. I remember the difference between slice and splice using a mnemonic. insert 'juliet' and 'zeke' at 3rd index // returns Ĭonsole. splice ( 3, 1, 'juliet', 'zeke' ) // remove 'harper'.












Array slice in javascript