源码

//219970525孙薇
//菜单收缩与扩展
function show(title) {
    let currentMenu = document.getElementById(title);
    let currentStatus = currentMenu.style.display;
    currentMenu.style.display = currentStatus == "" ? "none" : "";
}

//获取原始图片路径
function showImg() {
    //获取图片
    let fruit = document.getElementById('fruit');
    //获取图片src属性值
    let fruitSrc = fruit.getAttribute('src');
    //获取msg1
    let msg1 = document.getElementById('msg1');
    //将src属性值嵌入进msg1文本中
    msg1.innerHTML = fruitSrc;
}

//获取喜欢的水果
function getFruit() {
    //获取‘name’为'enjoy'的复选框
    let enjoyList = document.getElementsByName("enjoy");
    let chooseList = [];
    //循环遍历
    for (let index in enjoyList) {
        //如果被选中
        if (enjoyList[index].checked) {
            //添加进选择列表
            chooseList.push(enjoyList[index].value);
        }
    }
    //将选择列表嵌入msg2
    let msg2 = document.getElementById("msg2");
    msg2.innerHTML = '你喜欢的水果是：' + chooseList.toString();
}

//用于检查图片是否已经添加的变量
let checkImg = false;

//创建图片
function createImg() {
    //图片已添加
    if (checkImg) {
        return;
    }
    let img = document.createElement('img');
    //设置图片的路径
    img.src = './work02/grape.jpg';
    //添加进图定位置
    let station = document.getElementById('msg3');
    station.appendChild(img);

    checkImg = true;
}

//检查图片是否已经克隆
let imgCloned = false;

//克隆图片
function cloneImg() {
    //已克隆
    if (imgCloned) {
        return;
    }
    //获取图片元素
    let fruit = document.getElementById('fruit');
    //克隆图片
    let cloneImg = fruit.cloneNode(true);
    //嵌入位置
    let msg4 = document.getElementById('msg4');
    msg4.appendChild(cloneImg);

    imgCloned = true;
}

//改变图片
function changeImg() {
    //图片路径
    let imgSrc = './work02/grape.jpg';
    //获取图片
    let fruit = document.getElementById('fruit');
    //修改新路径
    fruit.src = imgSrc;
}

//删除图片
function removeImg() {
    //获取图片
    let img = document.getElementById('fruit');
    //获取父元素
    let parentElement = img.parentNode;
    //存在则移除
    if (parentElement) {
        parentElement.removeChild(img);
    }
}

//操作样式1
function changeCss1() {
    let fruit = document.getElementById('fruit');
    fruit.style.border = '2px solid red';
}

//操作样式2
function changeCss2() {
    let fieldsetList = document.getElementsByTagName('fieldset');
    for (let fieldset of fieldsetList) {
        fieldset.className = 'newcss1';
    }
}