JavaScript push в определенном индексе
arr.splice(index, 0, item);
//explanation:
inserts "item" at the specified "index",
deleting 0 other items before it
Dark Dotterel
arr.splice(index, 0, item);
//explanation:
inserts "item" at the specified "index",
deleting 0 other items before itconst items = [1, 2, 3, 4, 5]
const insert = (arr, index, newItem) => [
// part of the array before the specified index
...arr.slice(0, index),
// inserted item
newItem,
// part of the array after the specified index
...arr.slice(index)
]
const result = insert(items, 1, 10)
console.log(result)
// [1, 10, 2, 3, 4, 5]