9-7

大小写转换

<script type="text/javascript">
            var registor = "a123456",
            username = "A123456";
            console.log( username.toLowerCase() );
        </script>

定时器

setInterval(function() {
                console.log("I am setInterval");
            }, 1000);

清除定时器

            var clock = setInterval(function(){
                 console.log("I am clock");
            }, 1000);
            
            setTimeout(function(){
                clearInterval(clock);
            }, 10000)

截取字符串长度

<script type="text/javascript">
                    var title = "主席出席二十国集团领导人杭州峰会系列活动纪实";
                    document.write( title.substr(0, 10) + "...");
 </script>

数组的增删改查

<script type="text/javascript">
            var arr = ["orange", "mango", "banana", "sugar", "tea"];
            console.log(arr);
            arr.splice(2, 0, "fish");
            console.log(arr);
            arr.splice(5, 1);
            console.log(arr);
</script>

字符串的替换

<script type="text/javascript">
            var content = "abc";
            console.log( content.replace("b", "q") );
        </script>

打开一个新的页面

<script type="text/javascript">
            window.open("http://www.baidu.com","_blank","width=300, height=200");
        </script>

验证邮箱

<script type="text/javascript">
            var email = "shann@wengdocomcn",
                atPos = email.indexOf("@"),
                dotPos = email.lastIndexOf(".");
            console.log(atPos, dotPos);
            
            if( atPos <= 0 || dotPos < atPos ){
                alert("请输入正确的电子邮箱");
            }
        </script>

弹出对话框

<script type="text/javascript">
            var result = confirm("你确认删除？");
            console.log(result);
            if( result ){
                alert("正在删除中...");
            }else{
                alert("你取消了删除");
            }
        </script>

拆分字符串

 <script type="text/javascript">
            var username = "a123456";
            console.log(username.charAt(0));
            for(var i = 0; i < username.length; i++) {
                document.write('<span class="font' + i + '">' + username.charAt(i) + "</span>");
            }
        </script>

浏览记录后退

<script type="text/javascript">
            setTimeout(function(){
                history.back();
            }, 3000);
        </script>

<h1 id="title">我是h1标题</h1>
	    <script type="text/javascript">
	    	// 1. 定义变量title
	    	// 2. 获取到页面内的#title的元素节点=>title
	    	// 3. 修改title的内容为“我已经被修改了。”
	    	// 4. 修改title的字体颜色为红色
	    	
	    	// 1. 定义变量title
            // 2. 获取到页面内的#title的元素节点=>title
	    	var title = document.querySelector("#title");
	    	
	    	// 3. 修改title的内容为“我已经被修改了。”
	    	title.innerHTML = "我已经被修改了。";
	    	
	    	// 4. 修改title的字体颜色为红色
	    	title.style.color = "red";
	    </script>