如果我向<P>添加类，为什么这段jquery代码不能工作

Question

它起作用了

var tip = "<p>Most computers will open PDF documents automatically, but you may need to download <a title='Link to Adobe website-opens in a new window'";
tip +=" href='http://www.adobe.com/products/acrobat/readstep2.html' target='_blank'>Adobe Reader</a>.</p>";


if($("div#maincontent a[href*='.pdf']").length>0){
    $("div#maincontent").children(":last-child").after(tip);

但事实并非如此

var tip = "<p class="adobe-reader-download">Most computers will open PDF documents automatically, but you may need to download <a title='Link to Adobe website-opens in a new window'";
tip +=" href='http://www.adobe.com/products/acrobat/readstep2.html' target='_blank'>Adobe Reader</a>.</p>";


if($("div#maincontent a[href*='.pdf']").length>0){
    $("div#maincontent").children(":last-child").after(tip);

Answer 1

您在此处使用了双引号，此处显示为adobe-reader-download

var tip = "<p class="adobe-reader-download">

试试这个：

var tip = "<p class=\"adobe-reader-download\">

注意：如果对整个字符串使用单引号，则不需要转义双引号。