console 命令行工具 X clear

console

function alertSecond(){
    alert("第2次");
}
function changeColor(){
    if(this.style.color == "black"){
        this.style
    }
}
    var oBtn = document.getElementById("btn");

    oBtn.onclick = function(){
        alert("第1次");
    }
    oBtn.onclick = function(){
        alert("第2次");
    }
    oBtn.onclick = function(){
        alert("第3次");
    }

    oBtn.onclick = function(){
        alert("第1次");
        alert("第2次");
        alert("第3次");
    }


    oListenBtn.addEventListener("click", fuction(){
        alert("第1次");
    },false);

    oListenBtn.addEventListener("click",alertSecond,false);{
        alert("第3次");
    },false);
}

<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script>
      
    </script>
</head>
<body>
    <input id="btn" type="button" value="按钮"/>
    <br/>
    <br/>
    <input id="listenBtn" type="button" value="监听按钮"/>

    <div>
        <p id="content">广州新华学院</p>

        <button id="removeBtn">解除</button>
    </div>

    <div>
        <p id="content1">信息科学学院</p>

        <button id="removeBtn1">解除</button>
    </div>
</body>
</html>