正则表达式删除字符串中字符的开始到结尾

Question

我有这个字符串：

var string = "From: Jeremy<br />
 Sent: 22 Apr 2016 12:08:03</br />
 To: Mark<br />
 Subject: Another test email<br /><br />

 Hi Mark, 
<br />
I'm sending this email as a way to test the email! 
<br />
Cheers, 
<br />
Jeremy"

并且我想从头开始拼接该字符串，直到“主题”行之后，以便获得电子邮件正文内容。

到目前为止，我已经尝试过了：

string.substring(string.lastIndexOf('Subject'), string.length - 1)

但是此选项的确从字符串中返回主题行。

我可以使用正则表达式库吗？

Answer 1

使用string.replace可以执行以下操作：

var body = string.replace(/^[\s\S]*\s+Subject: [^\n]*\n+/, '')

码：

 var string = `From: Jeremy<br /> Sent: 22 Apr 2016 12:08:03</br /> To: Mark<br /> Subject: Another test email<br /><br /> Hi Mark, <br /> I'm sending this email as a way to test the email! <br /> Cheers, <br /> Jeremy` var body = string.replace(/^[\\s\\S]*\\s+Subject: [^\\n]*\\n+/, '') document.writeln("<pre>" + body + "</pre>") 

[\\s\\S]*匹配0个或多个任何字符，包括换行符。 紧随其后的是Subject:行。

输出：

"Hi Mark, 
<br />
I'm sending this email as a way to test the email! 
<br />
Cheers, 
<br />
Jeremy"

Answer 2

有人会给您非正则表达式的解决方案，但这是一个带有正则表达式的解决方案

[\s\S]*Subject\s*:.*([\s\S]+) <-- your result in first capturing group

正则表达式演示

JS演示

 var re = /[\\s\\S]*Subject\\s*:.*([\\s\\S]+)/gm; var str = `From: Jeremy<br /> Sent: 22 Apr 2016 12:08:03</br /> To: Mark<br /> Subject: Another test email<br /><br /> Hi Mark, <br /> I'm sending this email as a way to test the email! <br /> Cheers, <br /> Jeremy` var m = re.exec(str); document.writeln("<pre>" + m[1] + "</pre>");