批改状态:合格
老师批语:
:first伪类选择器相当于:eq(0)。它也可以写为:lt(1)。虽然:first只匹配一个单独的元素,但是:first-child选择器可以匹配多个:即为每个父级元素匹配第一个子元素。
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>学习笔记-Jquery</title><script src="https://code.jquery.com/jquery-3.1.1.min.js"></script><style type="text/css">*{padding: 0;margin: 0;}div {width: 500px;height: 60px;border: 1px solid;border-color: #000000;margin: 15px auto 0 auto;text-align: center;}.addCss {border-color: orangered;background: red;color: #FFF;font-size: 30px;}p {width: 500px;height: 50px;text-align: center;line-height: 50px;margin: 30px auto 0 auto;border: 1px solid #eee;background: #0356fa;cursor: pointer;color: #FFF;}</style></head><body><div>1</div><div>2</div><div>3</div><div>4</div><div>5</div><div>6</div><p type="button" onclick="clicks()">:first (点我选择第一个DIV)</p></body><script type="text/javascript">function clicks(){$('div:first').addClass('addCss');}</script></html>
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>学习笔记-Jquery</title><script src="https://code.jquery.com/jquery-3.1.1.min.js"></script><style type="text/css">*{padding: 0;margin: 0;}div {width: 500px;height: 60px;border: 1px solid;border-color: #000000;margin: 15px auto 0 auto;text-align: center;}.addCss {border-color: orangered;background: red;color: #FFF;font-size: 30px;line-height: 60px;}p {width: 500px;height: 50px;text-align: center;line-height: 50px;margin: 30px auto 0 auto;border: 1px solid #eee;background: #0356fa;cursor: pointer;color: #FFF;}</style></head><body><div>1</div><div>2</div><div>3</div><div>4</div><div>5</div><div>6</div><p type="button" onclick="clicks()">$('div:last')(点我选择最后一个DIV)</p></body><script type="text/javascript">function clicks(){$('div:last').addClass('addCss');}</script></html>
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>学习笔记-Jquery</title><script src="https://code.jquery.com/jquery-3.1.1.min.js"></script><style type="text/css">*{padding: 0;margin: 0;}div {width: 500px;height: 60px;border: 1px solid;border-color: #000000;margin: 15px auto 0 auto;text-align: center;}.addCss {border-color: orangered;background: red;color: #FFF;font-size: 30px;line-height: 60px;}p {width: 500px;height: 50px;text-align: center;line-height: 50px;margin: 30px auto 0 auto;border: 1px solid #eee;background: #0356fa;cursor: pointer;color: #FFF;}</style></head><body><div>1</div><div>2</div><div>3</div><div>4</div><div>5</div><div>6</div><p type="button" onclick="clicks()"> $('div:eq(2)')(点我选择) </p></body><script type="text/javascript">function clicks(){$('div:eq(2)').addClass('addCss');}</script></html>
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>学习笔记-Jquery</title><script src="https://code.jquery.com/jquery-3.1.1.min.js"></script><style type="text/css">*{padding: 0;margin: 0;}div {width: 500px;height: 60px;border: 1px solid;border-color: #000000;margin: 15px auto 0 auto;text-align: center;}.addCss {border-color: orangered;background: red;color: #FFF;font-size: 30px;line-height: 60px;}p {width: 500px;height: 50px;text-align: center;line-height: 50px;margin: 30px auto 0 auto;border: 1px solid #eee;background: #0356fa;cursor: pointer;color: #FFF;}</style></head><body><div>0</div><div>1</div><div>2</div><div>3</div><div>4</div><div>5</div><p type="button" onclick="clicks()"> $('div:lt(2)')(点我选择) </p></body><script type="text/javascript">function clicks(){$('div:lt(2)').addClass('addCss');}</script></html>
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>学习笔记-Jquery</title><script src="https://code.jquery.com/jquery-3.1.1.min.js"></script><style type="text/css">*{padding: 0;margin: 0;}div {width: 500px;height: 60px;border: 1px solid;border-color: #000000;margin: 15px auto 0 auto;text-align: center;}.addCss {border-color: orangered;background: red;color: #FFF;font-size: 30px;line-height: 60px;}p {width: 500px;height: 50px;text-align: center;line-height: 50px;margin: 30px auto 0 auto;border: 1px solid #eee;background: #0356fa;cursor: pointer;color: #FFF;}</style></head><body><div>0</div><div>1</div><div>2</div><div>3</div><div>4</div><div>5</div><p type="button" onclick="clicks()"> $('div:gt(0)')(点我选择) </p></body><script type="text/javascript">function clicks(){$('div:gt(0)').addClass('addCss');}</script></html>
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>学习笔记-Jquery</title><script src="https://code.jquery.com/jquery-3.1.1.min.js"></script><style type="text/css">*{padding: 0;margin: 0;}div {width: 500px;height: 60px;border: 1px solid;border-color: #000000;margin: 15px auto 0 auto;text-align: center;}.addCss {border-color: orangered;background: red;color: #FFF;font-size: 30px;line-height: 60px;}p {width: 500px;height: 50px;text-align: center;line-height: 50px;margin: 30px auto 0 auto;border: 1px solid #eee;background: #0356fa;cursor: pointer;color: #FFF;}</style></head><body><div id="a">0</div><div id="b">1</div><div id="c">2</div><div class="d">3</div><div id="e">4</div><div class="f">5</div><p type="button" onclick="clicks()"> $('div[id]')(点我选择有ID属性的DIV) </p></body><script type="text/javascript">function clicks(){$('div[id]').addClass('addCss');}</script></html>
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