删除从特定位置开始的未知数量的数组元素

Question

I am aware pop() will remove the last element in a JS array, and that shift() will remove the first one, and that slice() lets you remove elements from an array - and that you can specify what position to start at, and how many to remove, like so:

 let cities = ["New York", "Tokyo", "Perth", "Helsinki"]; cities.splice(2, 2); console.log(cities); 

What I'm wondering is if there's a method you can use to start at a certain array position, and remove any additional elements beyond that number?

Answer 1

Yeah, splice . Just do not provide the second argument

From Docs

deleteCount Optional

If deleteCount is omitted, or if its value is larger than array.length - start (that is, if it is greater than the number of elements left in the array, starting at start), then all of the elements from start through the end of the array will be deleted.

 let cities = ["New York", "Tokyo", "Perth", "Helsinki"]; cities.splice(2) console.log(cities) 

Answer 2

只需使用splice提供初始索引，它会假设您需要所有其他值，直到数组结尾

Answer 3

If you don't want to change original array use slice() by passing 0 as first argument

 let cities = ["New York", "Tokyo", "Perth", "Helsinki","Landon"]; let number = 1 console.log(cities.slice(0,number)); 

You can do that using splice() if you want to modify original array.

 let cities = ["New York", "Tokyo", "Perth", "Helsinki","Landon"]; let number = 1 cities.splice(number); console.log(cities);