Question

我有这个示例示例here。

  <div class="subchatarea2">
 <div  class='message_holder  user45 chatid28'>
<div class='likescore'>5</div><div class='unlikescore'>0</div>
</div>

<div  class='message_holder  user46 chatid29'>
<div class='likescore'>6</div><div class='unlikescore'>1</div>
</div>
<div  class='message_holder  user47 chatid30'>
<div class='likescore'>4</div><div class='unlikescore'>0</div>
</div>
<div  class='message_holder  user48 chatid31'>
<div class='likescore'>6</div><div class='unlikescore'>2</div>
</div>
</div>

我的js是

 var his = $('.subchatarea2 .message_holder'); 

 var maxvoteups = [];
  var diff = his.children('.likescore').text()-his.children('.unlikescore').text(); 

 his.each(function() {

  maxvoteups.push(diff);
});
 var maxvoteup = Math.max.apply(Math, maxvoteups);
 alert(maxvoteup);

我希望得到这样的结果（upvote和downvote之间的差异数组）：

  [5,5,4,4]

但是在我的页面中我得到了

  [5544,5544,5544,5544]

当我创造这个小提琴时，它会给你看到的结果。

我怎样才能得到我的愿望结果[5,5,4,4]，因为我想进一步选择最低投票最低投票数

 var maxvoteup = Math.max.apply(Math, maxvoteups);

然后我想获得第一个5，因为第二个5有downvote 1而第一个有downvote 0。

我怎么能完成这件事呢？

Answer 1

与@Jose的意图相同，但实现不同

var his = $('.subchatarea2 .message_holder'); 
var $votes = his.map(function(i, node){
    //first parse the text in the DOM into some data-structure
    var $node = $(node);
    return {
        node: $node,
        up: +$node.children('.likescore').text(),
        down: +$node.children('.unlikescore').text(),
        get diff(){
            return this.up - this.down;
        }
    };
}).sort(function(a, b){
    //and sort it by: `diff` desc, `down` asc
    return b.diff - a.diff || a.down - b.down;
});

//so your prefered value is at index 0
console.log("maxvoteup", $votes[0]);
console.log("votes", $votes);

Answer 2

 var his = $('.subchatarea2 .message_holder'); 

 var maxvoteups = []; 

 his.each(function() {
  var diff = $(this).children('.likescore').text() - $(this).children('.unlikescore').text();
  var downvotes = $(this).children('.unlikescore').text();
  maxvoteups.push([diff, downvotes]);
});

现在你有一个这样的清单：

[[5,0], [6,1], [4,0],[6,2]]

是[[totalvotes(total_up - total_down), total_downvotes]]

编辑：比这更好的是制作一个对象列表：

 var his = $('.subchatarea2 .message_holder'); 

 var maxvoteups = []; 

 his.each(function() {
  var diff = $(this).children('.likescore').text() - $(this).children('.unlikescore').text();
  var downvotes = $(this).children('.unlikescore').text();
  maxvoteups.push({total : diff, down : downvotes});
});

然后是一个比较对象的函数：

function compare(a,b) {
  if (a.total > b.total)
    return -1;
  else if (a.total < b.total)
    return 1;
  else if (a.down > b.down) // If a has more downvotes the a is under b.
    return -1;
  else if (a.down < b.down)
    return 1;
}

现在按如下顺序排列列表：

maxvoteups.sort(compare);

修改

最终代码：

var his = $('.subchatarea2 .message_holder');

var maxvoteups = [];

his.each(function() {
  var diff = $(this).children('.likescore').text() - $(this).children('.unlikescore').text();
  var downvotes = $(this).children('.unlikescore').text();
  var upvotes = $(this).children('.likescore').text();
  var node = $(this);
  maxvoteups.push({total : diff, downvotes : downvotes, upvotes : upvotes, node : node});

});
//var maxvoteup = Math.max.apply(Math, maxvoteups);
function compare(a,b) {
  if (a.total > b.total)
    return -1;
  else if (a.total < b.total)
    return 1;
  else if (a.down < b.down)
    return -1;
  else if (a.down > b.down)
    return 1;
}
maxvoteups.sort(compare);
alert('The max value is : ' + maxvoteups[0].total + ' with ' +  maxvoteups[0].upvotes + ' upvotes and ' +  maxvoteups[0].downvotes + ' downvotes and is the jquery element ' +  maxvoteups[0].node );

maxvoteups.forEach(function(post, index){
    alert('The' + (index + 1) + ' value of the sorted list is : ' + post.total + ' with ' +            post.upvotes + ' upvotes and ' +  post.downvotes + ' downvotes and is the jquery element ' +  post.node );
});

Answer 3

您需要将diff变量保留在循环中

 var his = $('.subchatarea2 .message_holder'); 
 var maxvoteups = [];
 var = 0;

 his.each(function() {
     diff = his.children('.likescore').text()-his.children('.unlikescore').text(); 
      maxvoteups.push(diff);
    });
 var maxvoteup = Math.max.apply(Math, maxvoteups);
 alert(maxvoteups);

Answer 4

一个简单的JS版本只不过是3行变量。类似的东西;

var    his = Array(...document.querySelectorAll('.subchatarea2 .message_holder')),
maxvoteups = his.map( e => e.firstElementChild.innerText - e.lastElementChild.innerText),
 maxvoteup = Math.max(...maxvoteups);

document.write("<pre>Array Values: " + maxvoteups + " Max Upvote: " + maxvoteup + "</pre>");

<div class="subchatarea2">
  <div  class='message_holder  user45 chatid28'>
    <div class='likescore'>5</div>
    <div class='unlikescore'>0</div>
  </div>
  <div  class='message_holder  user46 chatid29'>
    <div class='likescore'>6</div>
    <div class='unlikescore'>1</div>
  </div>
  <div  class='message_holder  user47 chatid30'>
    <div class='likescore'>4</div>
    <div class='unlikescore'>0</div>
  </div>
  <div  class='message_holder  user48 chatid31'>
    <div class='likescore'>6</div>
    <div class='unlikescore'>2</div>
  </div>
</div>

每个函数可以获得最大的差异数组

4 个答案:

修改