如何在正则表达式的开头和结尾删除空格?

时间:2015-01-15 11:51:42

标签: javascript regex parsing replace

我为我的标记语言创建了一个javascript解析器。 我希望标签和内容之间没有这样的空格:

__underline a sentence __and more. 
(or correctly : __underline a sentence__ and more.)

到:

<u>underline a sentence</u> and more.

但结果是第一种情况:

<u>underline a sentence </u>and more.

我的代码:

var tabML = ['\'','*','_'],
    tabHTML = ['em','strong','u']
    tag, char;
for(var i=0; i<tabML.length; i++){
    tag = tabHTML[i]; char = tabML[i];
    regex = new RegExp(char+char+'(.+)'+char+char, 'ig');
    txt = txt.replace(regex, '<'+tag+'>$1</'+tag+'>');
}

感谢。

2 个答案:

答案 0 :(得分:0)

使用以下正则表达式,然后将匹配的字符替换为<u>$1</u>

__\s*(.*?)\s*__\s*

DEMO

> var s1 = "__underline a sentence __and more."
undefined
> var s2 = "__underline a sentence__ and more."
undefined
> s1.replace(/__\s*(.*?)\s*__\s*/g, '<u>$1</u> ')
'<u>underline a sentence</u> and more.'
> s2.replace(/__\s*(.*?)\s*__\s*/g, '<u>$1</u> ')
'<u>underline a sentence</u> and more.'

答案 1 :(得分:0)

__(.*?)[ ]*__[ ]*

试试这个。<u>$1</u>。见。演示。

https://regex101.com/r/tX2bH4/5

var re = /__(.*?)[ ]*__[ ]*/gm;
var str = '__underline a sentence __and more.\n__underline a sentence__ and more.';
var subst = '<u>$1</u> ';

var result = str.replace(re, subst);