lovecoding
/
VIPJAVA


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>案例1</title>
</head>
<body>

    <img id="light" src="imgs/off.gif"> <br>

    <script>
        //定时器
        // 获取img元素
        // 标识 数字
        let number = 0;
        setInterval(function (){
            //获取元素
            let img = document.getElementById("light");
            //判断
            if ( number % 2 == 0 ){
                img.src =  "imgs/off.gif";
            }else{
                img.src =  "imgs/on.gif";
            }
            //标识改变
            number++;
        },1000)

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