#### Splice(拼接) vs Slice(切片)

- `splice()`: 原陣列會被修改，第二個參數代表要刪除的元素個數，之後的可選參數，代表要替補被刪除位置的元素。

```js
var months = ['Jan', 'March', 'April', 'June'];
months.splice(1, 0, 'Feb');
// inserts at index 1
console.log(months);
// expected output: Array ['Jan', 'Feb', 'March', 'April', 'June']

months.splice(4, 1, 'May');
// replaces 1 element at index 4
console.log(months);
// expected output: Array ['Jan', 'Feb', 'March', 'April', 'May']
```

- `slice()`: 不修改原陣列，按照參數複製一個新陣列，參數代表複製的起點及終點索引(省略則代表到末尾)，但`終點索引`的位置不包含在內。

```js
var animals = ['ant', 'bison', 'camel', 'duck', 'elephant'];

console.log(animals.slice(2));
// expected output: Array ["camel", "duck", "elephant"]

console.log(animals.slice(2, 4));
// expected output: Array ["camel", "duck"]

console.log(animals.slice(1, 5));
// expected output: Array ["bison", "camel", "duck", "elephant"]
```