SOURCE

console 命令行工具 X clear

                    
>
console
function alertSecond() 
{
    alert("2");
}


function changeColor() 
{
    if (this.style.color == "red") 
    {
        this.style.color = "black";
    }
    else {
         this.style.color = "red";
    }
   
}



function changeBackgroundColor() 
{
    if (this.style.backgroundColor == "lightskyblue") 
    {
        this.style.backgroundColor = "white";
    }
    else 
    {
         this.style.backgroundColor = "lightskyblue";
    }
   
}


window.onload = function () 
{
    var oBtn = document.getElementById("btn");

    oBtn.onclick = function () 
    {
        alert("1");
    };
    oBtn.onclick = function () 
    {
        alert("2");
    };
    oBtn.onclick = function () 
    {
        alert("1");
        alert("2");
        alert("3");
    };
     var oBtn = document.getElementById("listenBtn");
     oBtn.addEventListener("click", function()
     {
         alert("1");
     }, false);



     oBtn.addEventListener("click", alertSecond, false);
     oBtn.removeEventListener("click", alertSecond, false);


    var oPContent = document.getElementById("content");
    oPContent.addEventListener("click", changeColor, false);
    oPContent.addEventListener("click", changeBackgroundColor, false);


    var oBtn = document.getElementById("removeBtn");


    oBtn.addEventListener("click", function()
    {
        oPContent.removeEventListener("click", changeColor, false);
    }, false);


    var oPContent1 = document.getElementById("content1");
    oPContent1.onclick = changeColor;


    var oBtn1 = document.getElementById("removeBtn1");

     oBtn1.addEventListener("click", function(event)
     {
        alert(event.type);
        oPContent1.onclick = null;
    }, false);


    document.addEventListener("keydown", function(event) 
    {
        console.log(event.type);
        if (event.shiftKey || event.altKey || event.ctrlKey)
        {
            console.log("按了shit alt ctrl");
        }
        console.log("按了 " + event.keyCode);
    });


    document.addEventListener("keyup", function(event) 
    {
        console.log(event.type);
        console.log("松了 " + event.keyCode);
    })


}
<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script>
      
    </script>
</head>
<body>
    <input id="btn" type="button" value="111"/>
    <br/>
    <br/>
    <input id="listenBtn" type="button" value="监听"/>

    <div>
        <p id="content">新年快乐</p>
        <button id="removeBtn">解除</button>
    </div>

    <div>
        <p id="content1">五一快乐</p>
        <button id="removeBtn1">解除</button>
    </div>
</body>
</html>