Fly Birdゲームをjsで実装する全過程を詳しく解説

        var jsHeadTitle = document.getElementById("headTitle");// 获取标题var jsHeadBird = document.getElementById("headBird"); // 获取标题中小鸟var Y = 3;//标题的摆动幅度var index = 0;var imgArr = ["img/bird0.png","img/bird1.png"] //将小鸟图片路径放入一个数组，利用逐帧动画的原理做出小鸟翅膀摆动的样子var headWaveTimer = setInterval(headWave,200); //设置标题上下摆动的定时器function headWave() {
            Y *= -1;
            jsHeadTitle.style.top = jsHeadTitle.offsetTop + Y + "px";
            jsHeadBird.src = imgArr[index++];if (index == 2) {
                index = 0;
            }
        }

        var jsStartBtn = document.getElementById("startBtn");
        jsStartBtn.onclick = function() { //为start按键添加点击事件处理程序
            jsHeadTitle.style.display = "none"; //隐藏标题
            clearInterval(headWaveTimer); //关闭让标题摆动的定时器
            jsStartBtn.style.display = "none"; //隐藏按键//待添加功能//点击开始按键进入游戏界面
        }

function Block() {this.upDivWrap = null;this.downDivWrap = null;this.downHeight = baseObj.randomNum(0,150);//随机生成0-150之间的数，用于控制下管道的高度this.gapHeight = baseObj.randomNum(150,160);// 管道中间间隙宽度，通过调节大小，可以的控制游戏难度this.upHeight = 312 - this.downHeight - this.gapHeight;// 用来生成Div的方法this.createDiv = function(url, height, positionType, left, top) {var newDiv = document.createElement("div");
        newDiv.style.width = "62px";
        newDiv.style.height = height;
        newDiv.style.position = positionType;
        newDiv.style.left = left;
        newDiv.style.top = top;
        newDiv.style.backgroundImage = url;  //"url(/img/0.jpg)"return newDiv;
    };this.createBlock = function() {var upDiv1 = this.createDiv("url(img/up_mod.png)", this.upHeight + "px");var upDiv2 = this.createDiv("url(img/up_pipe.png)", "60px");this.upDivWrap = this.createDiv(null, null, "absolute", "450px");this.upDivWrap.appendChild(upDiv1);this.upDivWrap.appendChild(upDiv2);//生成上方管道var downDiv1 = this.createDiv("url(img/down_pipe.png)", "60px");var downDiv2 = this.createDiv("url(img/down_mod.png)", this.downHeight +"px");this.downDivWrap = this.createDiv(null, null, "absolute", "450px", 363 - this.downHeight + "px");this.downDivWrap.appendChild(downDiv1);this.downDivWrap.appendChild(downDiv2); //生成下方的管道

        jsWrapBg.appendChild(this.upDivWrap);
        jsWrapBg.appendChild(this.downDivWrap);
    };this.moveBlock = function() { //控制管道移动的方法this.upDivWrap.style.left = this.upDivWrap.offsetLeft - 3 + "px";this.downDivWrap.style.left = this.downDivWrap.offsetLeft - 3 + "px";
    };    
}

        <div id="score">
            <div id="num1"></div>
            <div id="num2"></div>
            <div id="num3"></div>
        </div>

#score{position:absolute;left: 130px;top:50px;z-index: 1;
}#score div{height: 39px;width: 28px;float: left;background-image: url(../img/0.jpg);display: none;
}

        var jsScore = document.getElementById("score");
        var jsNum1 = document.getElementById("num1");
        var jsNum2 = document.getElementById("num2");
        var jsNum3 = document.getElementById("num3");
        var score = 0;

jsNum1.style.display = "block";// 在点击开始之后，让计数器显示出来。

       if (blocksArr[0].downDivWrap.offsetLeft == -12) {score++;//积分面板
                if (score < 10) {jsNum1.style.backgroundImage = "url(img/" + score + ".jpg)";
            } else if (score < 100) {jsNum2.style.display = "block";jsNum1.style.backgroundImage = "url(img/" + parseInt(score/10) + ".jpg)";jsNum2.style.backgroundImage = "url(img/" + score%10 + ".jpg)";
            } else if (score < 1000) {jsNum3.style.display = "block";jsNum1.style.backgroundImage = "url(img/" + parseInt(score/100) + ".jpg)";jsNum2.style.backgroundImage = "url(img/" + parseInt(score/10)%10 + ".jpg)";jsNum3.style.backgroundImage = "url(img/" + score%10 + ".jpg)";
            }
                console.log(score);
        }

            <div id="gameOver">
                <img src="img/game_over.jpg" alt="game over" />
                <img src="img/message.jpg" alt="message" />
                <img id="ok" src="img/ok.jpg" alt="ok" />
            </div>

#gameOver{position: absolute;top: 100px;text-align: center;display: none;z-index: 1;
}

        jsOkBtn.onclick = function() {window.location.href = "index.html"; //刷新页面
        }