Javascript document.getElementsByClassName不返回所有元素 [英] Javascript document.getElementsByClassName not returning all elements

问题描述

我有以下javascript代码（纯js，没有libs），但是当它运行时它只返回一个元素而不是两个

I have the following javascript code (pure js, no libs), however when its run it only returns one element instead of two

function changeButtonStyles() {
    var actualButtons = document.getElementsByClassName("read-more");
    for (var i = 0; i < actualButtons.length; i++) {
        actualButtons[i].parentNode.className = "basic";
        actualButtons[i].className = "btn btn-xs btn-default";
    }

它应该从页面返回两个元素，所以我可以修改它们，但是它只返回一个或循环只迭代一个。这是为什么？

It should return two elements from the page so I can modify them both, but it only returns the one or the loop only iterates through one. Why is this?

jsfiddle

推荐答案

尝试按方法选择所有元素

Try select all elements by method

document.querySelectorAll(".read-more");

我更新小提琴 https://jsfiddle.net/rzdkr2gL/7/

你可以使用 forEach 方法

actualButtons.forEach(function (el) {
    el.parentNode.className = "basic";
    el.className = "btn btn-xs btn-default";
})

或（推荐方式）

Array.prototype.forEach.call(actualButtons, function (el) {
    el.parentNode.className = "basic";
    el.className = "btn btn-xs btn-default";
})

或

NodeList.prototype.forEach.call(actualButtons, function (el) {
    el.parentNode.className = "basic";
    el.className = "btn btn-xs btn-default";
})

最终代码可能看起来像 https：// js fiddle.net/rzdkr2gL/8/

Final code may be looks like https://jsfiddle.net/rzdkr2gL/8/

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