> For the complete documentation index, see [llms.txt](https://javascriptuse.gitbook.io/javascript/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://javascriptuse.gitbook.io/javascript/doan-ma-javascript-de-them-ky-tu-dac-biet-vao-dau-moi-dong-trong-van-ban-nhieu-dong-ok.md).
# Đoạn mã JavaScript để thêm ký tự đặc biệt vào đầu mỗi dòng trong văn bản nhiều dòng (ok)
### Bản nâng cấp
```html
Document
```
Bản gốc
```html
Document
```
---
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