Question

有人可以帮我修改这个JQuery代码，以便它进行减法计算而不是添加吗？

在这个当前代码中，第一个表只是一个保存数据的普通表，第二个表是用jQuery动态填充的，用于累加列。我不知道如何完成相同的功能只做减去列。我尝试替换+ = by - =并且仍然添加值，但在它们前面放置一个减号。例如，年龄列的年龄值为500,100,100和-700。

任何人都可以提供任何见解吗？

 <html> 
 <head> 
 <script type="text/javascript" SRC="https://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.js"></script> 

 </head> 
 <TABLE class=custom id=data> 
 <TBODY> 
 <TR> 
  <TH>name</TH> 
  <TH>age</TH> 
  <TH>weight</TH> 
  <TH>benchpress</TH> 
 </TR> 
 <TR> 
  <TD>stan</TD> 
  <TD>500</TD> 
  <TD>400</TD> 
  <TD>300</TD> 
 </TR> 
 <TR> 
  <TD>rj</TD> 
  <TD>100</TD> 
  <TD>50</TD> 
  <TD>50</TD> 
 </TR> 
 <TR> 
  <TD>jose</TD> 
  <TD>100</TD> 
  <TD>50</TD> 
  <TD>50</TD> 
 </TR> 
</TBODY> 
</TABLE> 
<BR> 
<TABLE class=custom> 
<TBODY> 
<TR> 
 <TH>ages</TH> 
 <TH>weights</TH> 
 <TH>benchpresses</TH> 
</TR> 
<TR> 
 <TD id=ages>&nbsp;</TD> 
 <TD id=weights>&nbsp;</TD> 
 <TD id=benchpresses>&nbsp;</TD> 
</TR> 
</TBODY> 
</TABLE> 
<script type="text/javascript">   

//these will hold the totals 
var ages = 0; 
var weights = 0; 
var benchpresses = 0; 

//reference the rows you want to add 
//this will not include the header row 
var rows = $("#data tr:gt(0)"); 
rows.children("td:nth-child(2)").each(function() { 
//each time we add the cell to the total 
ages -= parseInt($(this).text(),10); 
}); 
rows.children("td:nth-child(3)").each(function() { 
weights -= parseInt($(this).text(),10); 
}); 
rows.children("td:nth-child(4)").each(function() { 
benchpresses -= parseInt($(this).text(),10); 
}); 

//then output them to the elements 
$("#ages").html(ages); 
$("#weights").html(weights); 
$("#benchpresses").html(benchpresses); 

</script> 
</html>

Answer 1

这是一个具有起始值并从中减去的示例：

http://jsfiddle.net/nq8Nh/

//these will hold the totals 
var ages = 0; 
var weights = 0; 
var benchpresses = 0; 

// first row is starting value. 
var row1 = $("#data tr:eq(1)"); 
ages = parseInt(row1.children("td:nth-child(2)").text());
weights = parseInt(row1.children("td:nth-child(3)").text());
benchpresses = parseInt(row1.children("td:nth-child(4)").text());

 //reference the rows you want to add 
//this will not include the header row or first row 
var rows = $("#data tr:gt(1)"); 
rows.children("td:nth-child(2)").each(function() { 
//each time we add the cell to the total 
ages -= parseInt($(this).text(),10); 
}); 
rows.children("td:nth-child(3)").each(function() { 
weights -= parseInt($(this).text(),10); 
}); 
rows.children("td:nth-child(4)").each(function() { 
benchpresses -= parseInt($(this).text(),10); 
}); 

//then output them to the elements 
$("#ages").html(ages); 
$("#weights").html(weights); 
$("#benchpresses").html(benchpresses);

Answer 2

我认为这就像将-=更改为+=

一样简单

Answer 3

嗯，它没有添加值。它的作用是：

ages = 0 - 500 - 100 - 100 = -700

所以这是一个正确的减法。

JQuery加法与减法中的计算

3 个答案: