我正在尝试从图像数组中显示图像 - javascript

Question

我的主页上显示了一个图像，并希望用户单击下一个图像按钮，以便显示数组中的下一个图像。 我见过类似的问题并尝试解决问题，但似乎没有任何效果。 我认为代码是正确的，当用户点击“下一个图像”时，我似乎无法显示图像。 任何建议将不胜感激。

JS：

var images = ["/aboutmepages/imagesAM/SSR.jpeg", "/aboutmepages/imagesAM/ATA.png",
  "/aboutmepages/imagesAM/BC.jpg", "/aboutmepages/imagesAM/GCU.jpg"
];

var current = 0; //current image displayed

var change_img = document.getElementById("placeholder");

function next() {
  if (current >= 0) {
    current = images.length;
    current++;
  }
  change_img.src = images[current].src;
}

HTML

  <img src="/aboutmepages/imagesAM/SSR.jpeg" id="placeholder">
    
    <div id="display">
        <button class="button" onclick="next()">Next Image</button>
    </div>  

Answer 1

你必须添加src的image中images阵列使用current指数

function next() {
  if (current === images.length) current = 0;
  change_img.src = images[current++];
}

NOTE: I've used lorem-picsum for demo purpose. You can add yours link

 var images = [ "https://picsum.photos/200/300", "https://picsum.photos/200", "https://picsum.photos/200/300", "https://picsum.photos/200", "https://picsum.photos/200/300", "https://picsum.photos/200" ]; var current = 0; //current image displayed var change_img = document.getElementById("placeholder"); function next() { if (current === images.length) current = 0; change_img.src = images[current++]; } const button = document.querySelector("button"); button.addEventListener("click", next);

 <div id="display"> <button class="button">Next Image</button> </div> <img src="https://picsum.photos/200" id="placeholder" />

Answer 2

关键问题是这一行：

change_img.src = images[current].src;

它应该是

change_img.src = images[current];

因为数组中的任何元素都没有src属性，所以只有数组索引处的字符串。

与其检查current >= 0 （我们已经知道它将为零），不如检查current是否小于数组长度（因为数组使用从零开始的索引）。

 const images = [ 'https://dummyimage.com/100x100/00ff00/000', 'https://dummyimage.com/100x100/0000ff/fff', 'https://dummyimage.com/100x100/000/fff', 'https://dummyimage.com/100x100/fff/000', ]; const placeholder = document.getElementById('placeholder'); const button = document.querySelector('button'); button.addEventListener('click', next, false); let current = 0; function next() { if (current < images.length) { placeholder.src = images[current]; ++current; } } next();

 <button>Next</button> <img id="placeholder" />