truncate-string
[Basic Algorithm Scripting: Truncate a String | freeCodeCamp.org](https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-algorithm-scripting/truncate-a-string)
## 我写的，用了 substring(),concat()
```js function truncateString(str, num) { if (str.length <= num) { return str }
return str.substring(0, num).concat('…') }
console.log(truncateString('A-tisket a-tasket A green and yellow basket', 8)) ```
## slice()
```js function truncateString(str, num) { if (str.length <= num) { return str } return str.slice(0, num).concat('…') }
console.log(truncateString('A-tisket a-tasket A green and yellow basket', 8)) ```