> For the complete documentation index, see [llms.txt](https://jen-hsuan-hsieh.gitbook.io/javascript-node-js/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jen-hsuan-hsieh.gitbook.io/javascript-node-js/chapter1/12javascript-quan-gong-lve-ff1a-ke-fu-js-de-qi-guai-bu-fen/122xing-bie-yu-yun-suan-zi/1226yu-she-zhi.md).

# 1.2.2.6.預設值

* 設定function預設值的方法:

```
function greet(name) {
    name = name || '<Your name here>';
    console.log('Hello ' + name);    
}

greet('Tony');
greet();
```