web-js-优快云博客

本文链接：https://blog.youkuaiyun.com/Gradually_Wise/article/details/132213220

<html>
    <head>
        <title>基本语法</title>
    </head>
    <body>
        <script>
            // window.alert("js");
            // document.write("js");
            // console.log("js");
            
            // function add(a,b){
            //     return a+b;
            // }
           
            var result = function(a,b){
                return a + b;
            }
             // var result = add(11,10);
            // alert(result);

        </script>
    </body>
</html>

            var arr = [1,2,3,4];
            arr[6] = "java";
            console.log(arr);
            for (let i = 0; i < arr.length; i++) {
                console.log(arr[i]); 
            }
            arr.forEach(e => {
                console.log(e);
            });
            arr.push(12,"web");
            arr.splice(3,4);
            console.log(arr);

   var str = "  hello world ";
            console.log(str.length);
            console.log(str.charAt(5));
            console.log(str.indexOf("o"));
            var s = str.trim();
            document.write(s);
            console.log(str.substring(0,4));

            var user = {
                name : "jiabao",
                age : 23,
                gender : "male",
                eat(){
                    alert("chifan");
                }
            }
            alert(user.name);
            user.eat();            var user = {
                name : "jiabao",
                age : 23,
                gender : "male",
                eat(){
                    alert("chifan");
                }
            }
            alert(user.name);
            user.eat();

            var user = {
                name : "jiabao",
                age : 23,
                gender : "male",
                eat(){
                    alert("chifan");
                }
            }
            // alert(user.name);
            // user.eat();

            var json = '{"name":"老王","age":18,"gener":["nan","nv"]}';
            var jsonobject = JSON.parse(json);
            alert(jsonobject.name);
            var json = JSON.stringify(jsonobject);

            alert("吃饭了吗");
            var i = 0;
            setInterval(function(){
                i++;
                document.write("吃了" + i + "次");
            },2000)
            setTimeout(function(){
                document.write("吐了出来")
            },1000)
            confirm("您确定不吃？");

alert(location.href);

location.href = "https://www.itcast.cn"

            var picture = document.getElementsByName('picture')
            for (let i = 0; i < picture.length; i++) {
                var p = picture[i];
                p.src="../img/huawei.jpg";
            }
            var h = document.getElementsByTagName('div');
            for (let i = 0; i < h.length; i++) {
                const element = h[i];
                element.innerHTML+= "<font color = 'red'>666</font>";
            }
            var name = document.getElementsByName('hobby');
            for (let i = 0; i < name.length; i++) {
                const element = name[i];
                element.checked=true;
            }

<html>
    <head>
        <title>点击练习</title>
    </head>
    <body>
        <img id="p1" src="../img/alibaba.jpg"><br><br>
        <input type="button" id="up" value="点亮">
        <input type="button" id="blow" value="熄灭"><br><br>
        <input type="text" name = "point" value = "itcaAS"><br><br>
        <input type="checkbox" name="movie">电影
        <input type="checkbox" name="movie">旅游
        <input type="checkbox" name="movie">游戏<br><br>
        <input type="button" id="allup" value="全选">
        <input type="button" id="allcontrary" value="反选">

    </body>
    <script>
        document.getElementById('up').onclick=function(){
            var picture = document.getElementById('p1');
            picture.src = "../img/alibaba.jpg";
            alert("切换成功");
        }        
        document.getElementById('blow').onclick=function(){
            var picture = document.getElementById('p1');
            picture.src = "../img/huawei.jpg";
            alert("切换成功");
        }
        document.getElementsByName('point')[0].onfocus=function(){
            var big = document.getElementsByName('point')[0];
            big.value = big.value.toUpperCase();
        }        
        document.getElementsByName('point')[0].onblur=function(){
            const low = document.getElementsByName('point')[0];
            low.value = low.value.toLowerCase();
        }
        document.getElementById("allup").onclick=function(){
            const check = document.getElementsByName('movie');
            for (let i = 0; i < check.length; i++) {
                const element = check[i];
                element.checked=true;
            }
        }
        document.getElementById("allcontrary").onclick=function(){
            const check = document.getElementsByName('movie');
            for (let i = 0; i < check.length; i++) {
                const element = check[i];
                element.checked=false;
            }
        }
    </script>
</html>