谷歌關閉編譯推進：在編譯時

Question

刪除代碼塊。如果我把這個代碼和編譯（高級優化）

/**@constructor*/ 
function MyObject() { 
    this.test = 4 
    this.toString = function() {return 'test object'} 
} 
window['MyObject'] = MyObject 

我得到這個代碼

window.MyObject=function(){this.test=4;this.toString=function(){return"test object"}}; 

有什麼辦法，我可以使用Closure編譯器去掉toString函數？

Answer 1

toString是隱式調用的，所以除非Closure編譯器可以證明MyObject的結果永遠不會被強制爲一個字符串，它必須保留它。

您可以隨時將其標記爲明確的調試代碼：

this.test = 4; 
if (goog.DEBUG) { 
    this.toString = function() { return "test object"; }; 
} 

然後在非調試版本，編譯

goog.DEBUG = false; 

見http://closure-library.googlecode.com/svn/docs/closure_goog_base.js.source.html這確實

/** 
* @define {boolean} DEBUG is provided as a convenience so that debugging code 
* that should not be included in a production js_binary can be easily stripped 
* by specifying --define goog.DEBUG=false to the JSCompiler. For example, most 
* toString() methods should be declared inside an "if (goog.DEBUG)" conditional 
* because they are generally used for debugging purposes and it is difficult 
* for the JSCompiler to statically determine whether they are used. 
*/ 
goog.DEBUG = true;