JavaScript web编程

百度换肤

<style>
        * {
     
            margin: 0;
            padding: 0;
        }
        
        list {
     
            list-style: none;
        }
        
        body {
     
            background: url(picture/1.jpg) no-repeat center top;
        }
        
        .baidu {
     
            overflow: hidden;
            margin: 100px auto;
            width: 410px;
            background-color: #fff;
            padding-top: 4px;
        }
    </style>
<body>
    <ul class="baidu">
        <li><img src="picture/1.jpg" alt=""></li>
        <li><img src="picture/2.jpg" alt=""></li>
        <li><img src="picture/3.png" alt=""></li>
        <li><img src="picture/4.jpg" alt=""></li>
    </ul>
    <script>
        var imgs = document.querySelector('.baidu').querySelectorAll('img');
        for (var i = 0; i < imgs.length; i++) {
     
            imgs[i].onclick = function() {
     
                document.body.style.backgroundImage = 'url(' + this.src + ')';
            }
        }
    </script>
</body>

显示隐藏文本框内容

<body>
    <input type="text" value="手机">
    <script>
        var text = document.querySelector('input');
        // 获得焦点
        text.onfocus = function() {
     
                if (this.value === '手机') {
     
                    this.value = '';
                }
                this.style.color = '#333';
            }
            // 失去焦点
        text.onblur = function() {
     
            if (this.value === '') {
     
                this.value = '手机';
            }
            this.style.color = '#999'
        }
    </script>
</body>

排他思想实现按钮变色

<body>
    <button>按钮1</button>
    <button>按钮2</button>
    <button>按钮3</button>
    <button>按钮4</button>
    <button>按钮5</button>
</body>
<script>
    var btns = document.getElementsByTagName('button');
    for (var i = 0; i < btns.length; i++) {
     
        btns[i].onclick = function() {
     
            for (var i = 0; i < btns.length; i++) {
     
                btns[i].style.backgroundColor = '';
            }
            this.style.backgroundColor = 'pink';
        }

    }
</script>

三个非常基础的案例,适用于初学者写网页的运用,通过自己的创造和灵感能够写出许多有意思的网页效果,js可以给网页更多的动态效果,使网站更加的灵活。

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