es6 删除数组中指定对象并返回新数组
2020-02-12 本文已影响0人
yuyuuuumi
If you know the index of an item
Suppose you have an array, and you want to remove an item in position i.
One method is to use slice():
const items = ['a', 'b', 'c', 'd', 'e', 'f']
const i = 2
const filteredItems = items.slice(0, i).concat(items.slice(i + 1, items.length))
// ["a", "b", "d", "e", "f"]
If you know the value
In this case, one good option is to use filter(), which offers a more declarativeapproach:
const items = ['a', 'b', 'c', 'd', 'e', 'f']
const valueToRemove = 'c'
const filteredItems = items.filter(item => item !== valueToRemove)
// ["a", "b", "d", "e", "f"]
Removing multiple items
By index
You can just create a function and remove items in series:
const items = ['a', 'b', 'c', 'd', 'e', 'f']
const removeItem = (items, i) =>
items.slice(0, i-1).concat(items.slice(i, items.length))
let filteredItems = removeItem(items, 3)
filteredItems = removeItem(filteredItems, 5)
//["a", "b", "c", "d"]
By value
You can search for inclusion inside the callback function:
const items = ['a', 'b', 'c', 'd', 'e', 'f']
const valuesToRemove = ['c', 'd']
const filteredItems = items.filter(item => !valuesToRemove.includes(item))
// ["a", "b", "e", "f"]
Avoid mutating the original array
splice() (not to be confused with slice()) mutates the original array, and should be avoided.