安全に[[配列 (JavaScript)|配列]]の一部要素を挿入/削除する[[配列 (JavaScript)|Arrayオブジェクト]]のメソッド。
```js
const xs = ["a", "i", "u"];
console.log(xs.toSpliced(1, 1));
// ["a", "u"]
console.log(xs);
// ["a", "i", "u"]
```
<button class="playground"><a href="https://www.typescriptlang.org/play?target=99&ts=5.2.2#code/MYewdgzgLgBAHhGBeGBtARAQ3QGhugS13wFd0BdAbgFgAoUSEAGwFMA6JkAcwAoE2oIAMoAHJgWAsAJjwCMeWQEpFNWgHo1aLMXRlydBhGbtOvBCroat2PIR166QA">Playground</a></button>