无论如何在点击事件被触发时获取该类.我的代码如下,它只适用于id但不适用于class.
$(document).ready(function() {
$("a").click(function(event) {
alert(event.target.id + " and " + event.target.class);
});
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<html>
<body>
<a href="#" id="kana1" class="konbo">click me 1</a>
<a href="#" id="kana2" class="kinta">click me 2</a>
</body>
</html>这里有 jsfiddle代码
以下代码无效.正如你在jsfiddle上看到的那样,我需要按列加总.出了什么问题？
<table id="sum_table" width="300" border="1">
<tr>
<td>Apple</td>
<td>Orange</td>
<td>Watermelon</td>
</tr>
<tr>
<td class="rowDataSd">1</td>
<td class="rowDataSd">2</td>
<td class="rowDataSd">3</td>
</tr>
<tr>
<td class="rowDataSd">1</td>
<td class="rowDataSd">2</td>
<td class="rowDataSd">3</td>
</tr>
<tr>
<td class="rowDataSd">1</td>
<td class="rowDataSd">2</td>
<td class="rowDataSd">3</td>
</tr>
<tr class="totalColumn">
<td class="totalCol">Total:</td>
<td class="totalCol">Total:</td>
<td class="totalCol">Total:</td>
</tr>
</table>
$(document).ready(function(){
$(".rowDataSd").each(function() {
newSum.call(this);
});
});
function newSum() {
var $table = $(this).closest('table');
var total = 0;
$(this).attr('class').match(/(\d+)/)[1];
$table.find('tr:not(.totalColumn) .rowDataSd').each(function() {
total += parseInt($(this).html());
});
$table.find('.totalColumn td:nth-child('')').html(total);
}
假设我有一个名为的文本文件:data.txt(包含2000行)
如何读取给定的特定行:500-1500然后1500-2000并显示特定行的输出？
此代码将读取整个文件(2000行)
public static String getContents(File aFile) {
StringBuffer contents = new StringBuffer();
try {
BufferedReader input = new BufferedReader(new FileReader(aFile));
try {
String line = null;
while (( line = input.readLine()) != null){
contents.append(line);
contents.append(System.getProperty("line.separator"));
}
}
finally {
input.close();
}
}
catch (IOException ex){
ex.printStackTrace();
}
return contents.toString();
}
如何修改上面的代码以读取特定的行？
我的架构看起来像这样:
CREATE TABLE users
(
id int auto_increment primary key,
name varchar(20),
point int(255)
);
INSERT INTO users
(name, point)
VALUES
('Jack', 1),
('Rick', 5),
('Danny', 11),
('Anthony', 24),
('Barla', 3),
('James', 15),
('Melvin', 12),
('Orthon', 5),
('Kenny', 2),
('Smith', 30),
('Steven', 27),
('Darly', 45),
('Peter', 44),
('Parker', 66),
('Lola', 78),
('Jennifer', 94),
('Smart', 87),
('Jin', 64),
('David', 31),
('Jill', 78),
('Ken', 48),
('Martin', 19),
('Adrian', 20),
('Oliver', 16),
('Ben', 100);
我的sql是:
select id, name, point from users Order by …