找一个最常见的类

Question

我很抱歉这个问题的形式。我知道应该包括一些代码，但我甚至不知道从哪里开始。我需要找到在div中最常见的类，其中包含一个特定的符号。问题是找出最常见的问题。

假设有一些div

<div class="mainclass subclass-1 subclass1"></div>
<div class="mainclass subclass-1 subclass3"></div>
<div class="mainclass subclass-2 subclass3"></div>
<div class="mainclass subclass-1 subclass2"></div>
<div class="mainclass subclass-1 subclass1"></div>

如何找到子类的总数-1(在本例中？)。类是动态生成的，我从不知道每次哪个类最常见。

Answer 1

您可以从下面的代码中找到类的完整列表及其计数。

var classes = new Object();

$("*").each(function() {
    if (this.className.length > 0)
    {
        var arrTmp = this.className.split(" ");
        for (var i=0; i<arrTmp.length; i++)
        {
            if ($.trim(arrTmp[i]).length > 0)
            {
                if (classes[arrTmp[i]])
                    classes[arrTmp[i]] = classes[arrTmp[i]] + 1;
                else
                    classes[arrTmp[i]] = 1;
            }
        }
    }    
});

var sortable = [];
for (var arr in classes)
      sortable.push([arr, classes[arr]])
sortable.sort(function(a, b) {return b[1] - a[1]});

alert(sortable);

在JsFiddle：https://jsfiddle.net/qsfdm286/上的测试

Answer 2

你可以的

var counter = {}, //to store the count of occurences temporarely
max; //the most common class
//iterate over te main class
$('.mainclass').each(function () {
    //find the subclass-* value
    var cs = this.className.match(/subclass-\d+/)[0];
    counter[cs] = counter[cs] || 0;
    //increment the count of occurrence
    counter[cs]++;
    if (counter[cs] > (counter[max] || 0)) {
        //if the current one is more then change the max to current class
        max = cs;
    }
});
console.log(max)

演示：小提琴

如果你也想考虑subclass1的话

var counter = {}, //to store the count of occurences temporarely
max; //the most common class
//iterate over te main class
$('.mainclass').each(function () {
    //find the subclass-* value
    var parts = this.className.match(/subclass-?\d+/g);
    $.each(parts, function (i, cs) {
        counter[cs] = counter[cs] || 0;
        //increment the count of occurrence
        counter[cs]++;
        if (counter[cs] > (counter[max] || 0)) {
            //if the current one is more then change the max to current class
            max = cs;
        }
    })
});
console.log(max, counter)

演示：小提琴

Answer 3

当您了解该类时，您可以按以下方式查找该类的用法：

var classList = document.getElementById('divId').className.split(/\s+/);
for (var i = 0; i < classList.length; i++) {
   var numItems = $('.'+classList[i]).length;
   console.log('Usage of class '  classList[i] 'is ' numItems ) 
}