Javascript Javascript在构造函数中调用原型函数
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/14441156/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Javascript calling prototype functions in constructor
提问by Danny
I keep getting an error saying that my functions are not defined when I was trying to call the prototype functions in the constructor and I dont know whats wrong with it.
当我试图在构造函数中调用原型函数时，我一直收到一个错误，说我的函数没有定义，我不知道它有什么问题。
Here's the code I have:
这是我的代码：
function Renderer()
{
initialiseWebGL();
initialiseShader();
initialiseBuffer();
}
Renderer.prototype.initialiseWebGL()
{
//Do stuff.
};
Renderer.prototype.initialiseShader()
{
//Do Shader's stuff
};
Renderer.prototype.initialiseBuffer()
{
//Do Buffers
};
What is wrong with it?
它有什么问题？
回答by Minko Gechev
Your syntax is wrong. Use this:
你的语法是错误的。用这个：
function Renderer() {
this.initialiseWebGL();
this.initialiseShader();
this.initialiseBuffer();
}
Renderer.prototype.initialiseWebGL = function () {
//Do stuff.
};
Renderer.prototype.initialiseShader = function () {
//Do Shader's stuff
};
Renderer.prototype.initialiseBuffer = function () {
//Do Buffers
};
After that you can create new object and use it by:
之后，您可以创建新对象并通过以下方式使用它：
var rendererInstance = new Renderer();
回答by Moritz Roessler
There are a few things wrong with your Code
您的代码有一些问题
1.initialiseWebGl()would look for a function declared in the Global scope -> there is no function
1.initialiseWebGl()会寻找在全局范围内声明的函数 -> 没有函数
- You should use
this.initialiseWebGl()to access the Objects Method
Note:thisrefers to the Instance ofRendererin this case
- 您应该使用
this.initialiseWebGl()访问 Objects 的方法
注意：在这种情况下this指的是 InstanceRenderer
2.You are not assigning a function with Renderer.prototype.initialiseWebGL()instead you try to invoke the Renderers prototype method initialiseWebGlwhich gives you an error, as its not defined
2.您没有分配函数，Renderer.prototype.initialiseWebGL()而是尝试调用Renderers 原型方法initialiseWebGl，该方法会给您一个错误，因为它未定义
3.Because the {are moved down a line they get interpreted as a Block -> this code gets executed.
If you'd had them after your ()you would get a Syntax Error->
Renderer.prototype.initialiseWebGL() {...would result in Uncaught SyntaxError: Unexpected token {
3.因为{它们被向下移动了一行，所以它们被解释为一个块 -> 此代码被执行。
如果你在你之后拥有它们，()你会得到一个语法错误->
Renderer.prototype.initialiseWebGL() {...会导致Uncaught SyntaxError: Unexpected token {
Heres an Commented Example
这是一个注释示例
function Renderer() {
initialiseWebGL(); // I call the global declared function
this.initialiseShader(); //I call the Prototypes function
this.initialiseBuffer(); //Me too
}
Renderer.prototype.initialiseWebGL = function (){ //Here a function gets assigned to propertie of `Renderer`s `prototype` Object
//Do stuff.
};
Renderer.prototype.initialiseShader = function (){
console.log("Do Shader Stuff");
};
Renderer.prototype.initialiseBuffer = function (){
console.log("Do initialise stuff");
};
Renderer.prototype.initialiseBuffer() // I invoke the method above
{
console.log("I'm a Block statement");
};
function initialiseWebGL () { //I'm the global declared function
console.log("Global");
}
var ren1 = new Renderer();
/*"Do initialise stuff"
"I'm a Block statement"
"Global"
"Do Shader Stuff"
"Do initialise stuff"*/
As you can see in the consoles Output
正如您在控制台输出中看到的那样
Heres a JSBin
这是一个JSBin
回答by Bergi
Since your instances inherit the (method) propertiesfrom the prototype objects, you need to access them as properties and not as plain variables:
由于您的实例从原型对象继承了（方法）属性，因此您需要将它们作为属性而不是普通变量来访问：
function Renderer() {
this.initialiseWebGL();
this.initialiseShader();
this.initialiseBuffer();
}
