$ .each(selector)和$(selector).each()有什么区别 [英] What is the difference between $.each(selector) and $(selector).each()

问题描述

这有什么区别:

$.each($('#myTable input[name="deleteItem[]"]:checked').do_something());

和这个:

$('#myTable input[name="deleteItem[]"]:checked').each(function() { do_something });

正在被选择并作用的表格单元格的html看起来像这样:

The html for the table cell that is being selected and acted upon looks like this:

<td width="20px"><input type="checkbox" class="chkDeleteItem" name="deleteItem[]" value="' . $rowItem['itemID'] . '" /></td>

我已经阅读了jQuery文档，但是我仍然不了解它们之间的区别. (是我还是该文档有时在内容的清晰度上有些模糊"?)

I've gone over the jQuery documentation, but I still don't understand the difference. (Is it me or is that documentation sometimes slightly "nebulous" in clarity of content?)

添加的信息:

显然我的尝试是一个通用示例，令人困惑！以及第一个示例中(以前)缺少的括号. :(

Apparently my attempt a generic examples is confusing people! Along with the (previously) missing parenthesis in the first example. :(

第一个示例来自我代码中的一行，该行删除了< tbody>对于带有已选中复选框的任何行:

The first example comes from a line in my code that removes the <tbody> for any rows with a checkbox that is checked:

$.each($('#classesTable input[name="deleteClasses[]"]:checked').parent().parent().parent().remove());

第二个示例来自以下情况:我在#classesTable中查看所有选中的复选框，然后在下拉列表中删除其匹配项.

The second example comes from a situation where I look through the #classesTable for any checked checkboxes and remove its matching item in a dropdown.

$('#classesTable input[name="deleteClasses[]"]:checked').each(function(){
    $('#classesList option[value="' + $(this).attr('value') + '"]').remove();
});

我知道他们做了两种不同的事情，但是我不能说在这种情况下，我需要使用$ .each()，而在另一种情况下，需要使用.each(function(){}).情况.

I understand that they do two different things, but not to the point that I'd be able to say "I need to use $.each() in this case and .each(function() {}) in another case.

它们是否可以互换?仅在某些情况下?从来没有?

Are they interchangeable at all? Only in some cases? Never?

推荐答案

说明:

.each是用于仅对jQuery进行迭代的迭代器 jQuery.each($.each)是常规对象时进行对象收集 用于遍历JavaScript对象和数组的函数.

.each is an iterator that is used to iterate over only jQuery objects collection while jQuery.each ($.each) is a general function for iterating over JavaScript objects and arrays.

---

示例

1)使用$.each() 函数

---

Examples

1) Using $.each() function

var myArray = [10,20,30];

$.each( myArray, function(index, value) {
   console.log('element at index ' + index + ' is ' + value);
});

//Output
element at index 0 is 10
element at index 1 is 20
element at index 2 is 30

2)使用.each() 方法

2) Using .each() method

$('#dv').children().each(function(index, element) {
    console.log('element at index ' + index + 'is ' + (this.tagName));
    console.log('current element as dom object:' + element);
    console.log('current element as jQuery object:' + $(this));
});

//Output
element at index 0 is input
element at index 1 is p
element at index 2 is span

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资源

• https://api.jquery.com/jquery.each/
• http://api.jquery.com/each/
• 用jQuery遍历具有相同类的元素

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Resources

• https://api.jquery.com/jquery.each/
• http://api.jquery.com/each/
• jQuery to loop through elements with the same class

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