Javascript RegExp lookbehind

Question

我有以下问题。我想在Javascript

中的以下字符串中替换“snippet”一词

<p>This is a <span class="snippet-expansion">snippet<span><p>

但我想保留class =“snippet-expansion”。

另一个案例可能是

<p>This is a snippet within a text<p>

第二种情况的结果应该是

<p>This is a <span class="highlight-searchterm">snippet</span> within a text<p>

通常，我会在正则表达式中使用lookbehind来做到这一点，但这些在Javascript中不可用。

是的，有人能帮帮我吗？

Answer 1

使用先行：

/snippet(?!-expansion)/

REF： https://regex101.com/r/lH5vA3/1

Answer 2

试试这个表达

var str='<p>This is a <span class="snippet-expansion">snippet<span><p>';

str.replace(/snippet.*?(\W|\s)+/g,function (val){ if(val.trim().match(/\W+/g) && !val.match(/</g)) return val; return val.replace(/snippet/g,'')  });

Answer 3

在结束标记>和开始标记<之间查找文字应该适用于您的情况。

＆＃13;

＆＃13;

var str = '<p>This is a <span class="snippet-expansion">snippet<span><p>';
var rep = str.replace(/(>[^<>]*)snippet([^<>]*<)/, "$1foo$2");
document.getElementById("t").value = rep;
document.getElementById("t").value += "\n\n";

var str1 = '<p>This is a snippet within a text<p>';
var rep1 = str1.replace(/(>[^<>]*)snippet([^<>]*<)/, "$1foo$2");
document.getElementById("t").value += rep1;
document.getElementById("t").value += "\n\n";

var str2 = '<p>This is a <span class="highlight-searchterm">snippet</span> within a text<p>';
var rep2 = str2.replace(/(>[^<>]*)snippet([^<>]*<)/, "$1foo$2");
document.getElementById("t").value += rep2;

＆＃13;

<textarea id="t" style="width: 500px; height: 200px;"></textarea>

＆＃13;

＆＃13;

＆＃13;