JavaScript开关灯小案例

• 1.效果
• 2.代码

1.效果

2.代码

<button id="btn">关灯</button>
			<script>
			var bodys = document.body;
			var btn =document.querySelector('#btn');
			var flag = 0;
			btn.onclick =function(){
				if(flag == 1){
				bodys.style.backgroundColor = 'black';
				btn.innerHTML = '开灯';
				flag = 0;
				}else{
					bodys.style.backgroundColor = 'white';
					btn.innerHTML = '关灯';
					flag = 1;
				}
			}
			</script>