javascript element.querySelector(".exampleClass") 不是函数
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element.querySelector(".exampleClass") is not a function
提问by user3562480
I am trying to build a responsive carousel and am getting an error in the following code. I've tried using JQuery, other selection methods but they all return the same error.
我正在尝试构建响应式轮播，但在以下代码中出现错误。我试过使用 JQuery 和其他选择方法，但它们都返回相同的错误。
I try to select the element here, first my accessing its parent element
我尝试在这里选择元素，首先我访问它的父元素
var carousel = $('#carousel');
var container = carousel.querySelector('.carousel-container');
The about code returns and ERROR that carousel.querySelector is not a function.
关于代码返回和错误，carousel.querySelector 不是一个函数。
Which creates a problem, and also screws up the resizing function below:
这产生了一个问题，并且还搞砸了下面的调整大小功能：
function slideTo(index){
index = index < 0 ? totalItems -1 : index >= totalItems ? 0 : index;
container.style = container.style.transform = 'translate(-' + (index * percent) + '%, 0)';
currentIndex = index;
}
Container.style in the third line of the function returns an ERROR that I cannot set a property on container.style as it is "undefined"
函数第三行中的 Container.style 返回一个错误，我无法在 container.style 上设置属性，因为它是“未定义的”
I REALLY just need to be able to add the CSS "transform : translate" property to the container element.
我真的只需要能够将 CSS“transform : translate”属性添加到容器元素。
I am at a loss for things to try... would really appreciate some feedback!
我对尝试的事情感到茫然......真的很感激一些反馈！
回答by chiliNUT
querySelectoris a native JS method, and carouselis a jQueryobject. If you are using jQuery, there is 0 reason to be using queryselector.
querySelector是一个原生的JS方法，并且carousel是一个jQuery对象。如果您正在使用jQuery，则有 0 个理由使用queryselector.
jQuery
jQuery
var carousel = $('#carousel'); //jQuery object
var container = carousel.find('.carousel-container'); //jquery object of carousel-container
DOM
DOM
var domCarousel=carousel.find('.carousel-container')[0];
which is roughly equivalent to
这大致相当于
domCarousel=document.getElementById('carousel').querySelector('.carousel-container');
