console 命令行工具 X clear

console

function alertSecond(){
    alret("第二次");
}

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("第一次");
    }

    oBtn.onclick = function(){
        alert("第二次");
    }

    oBtn.onclick = function(){
        alert("第三次");
    }

    oBtn.onclick = function(){
        alert("第一次");
        alert("第二次");
        alert("第三次");
    }


    var oListenBtn = document.getElementById("ListenBtn");

    oListenBtn.addEventListener("click",function(){
        alert("第一次");
    },false);

    oListenBtn.addEventListener("click",alertSecond,false);

    function alertThird(){
        alert("第三次");
    }

    oListenBtn.addEventListener("click",alertSecond,false);

    oListenBtn.renoveEventListener("click",alertSecond,false);

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

    var oRemveBtn = document.getElementById("removBtn");
    oRemveBtn.addEventListener("click", function(){
        oPContent.removeEventListener("click", changeColor,false);
    },false);

    var oPContent1 = document.getElementById("content1");
    oPContent1.onclick = function(){
        if(this.style.color == rad){
            this.style.color = "black";
        }
        else{
            this.style.color = "red";
        }

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

    var oRomvcBtn1 = document.getElementById("removcBtn1");
    oRenveBtn1.addEventListener("click", function(){
        oPContent1.onclick = function(){
            if (this.style.backgroundColor = "lightskyblue"){
                this.style.backgroundColor = "white";
            }
            else{
                this.style.backgroundColor = "lightskyblue";
            }
        }
    },falsee);





document.addEventListener("keydown", function(event){
        console.log(event.type);
        console.log("你按下 " + event.keyCode);
        if (event.altKey) {
            console.log("你按下了Alt");
        }
        if (event.ctrlKey) {
            console.log("你按下了Ctrl");
        }
        if (event.shiftKey) {
            console.log("你按下了Shift");
        }
    }, false)

    document.addEventListener("keyup", function(event){
        console.log(event.type);
        console.log("你松开 " + event.keyCode);
        if (event.altKey) {
            console.log("你松开了Alt");
        }
        if (event.ctrlKey) {
            console.log("你松开了Ctrl");
        }
        if (event.shiftKey) {
            console.log("你松开了Shift");
        }
    }, 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>