將 http 轉換成 a tag

str.replace(/https?:\/\/([-\w\.]+)+(:\d+)?(\/([^\s]*(\?\S+)?)?)?/g, '$&');

我自己常常用的如下

text = text.replace(/https?:\/\/([-\w\.]+)+(:\d+)?(\/([^\s]*(\?\S+)?)?)?/g, '<a target="_blank" href="$&">$&</a>');