删除与JavaScript的按钮

Question

我想删除按钮后，它被点击（该按钮是在JavaScript中创建），并从不同的职位，它表示此代码将工作，但在我的控制台我得到的错误：

Uncaught TypeError: Cannot read property 'remove' of null 
at HTMLUnknownElement.<anonymous> (RBrOJeLwYgRM:335) 

为什么？帮帮我！ 代码：

Element.prototype.remove = function() { 
    this.parentElement.removeChild(this); 
} 
NodeList.prototype.remove = HTMLCollection.prototype.remove = function() { 
    for(var i = this.length - 1; i >= 0; i--) { 
     if(this[i] && this[i].parentElement) { 
      this[i].parentElement.removeChild(this[i]); 
     } 
    } 
} 

我的代码，激活删除功能：

else if (PaintBrush.crashWith(Finish)) { 
     PaintBrush.y = 50; 
     var button = document.createElement("button2"); 
button.innerHTML = "Level 2"; 
     var body = document.getElementsByTagName("body")[0]; 
body.appendChild(button); 
     GameArena.clear(); 
     GameArena.stop(); 
     button.addEventListener ("click", function() { 
    startGame2(); 
     document.getElementById("button-2").remove(); 
}); 

Answer 1

尝试这些变化

PaintBrush.y = 50; 
var button = document.createElement("button"); // remove the "2" 
button.innerHTML = "Level 2"; 
button.id = "button-2"; // add the id to the button 
document.body.appendChild(button); // append to body 
GameArena.clear(); 
GameArena.stop(); 
button.addEventListener ("click", function() { 
    startGame2(); 
    document.getElementById("button-2").remove(); 
});