類型推斷在使用局部變量的時候節省了大量手工類型化，但是有時類型系統仍然需要一些幫助。事實上，它甚至不嘗試推斷變量（第4.1節）或者屬性（第4.2節）字段，除非它有一個直接的初始化。 > Type inference saves a lot of manual type hints when working with local variables,but sometimes the type system still needs some help. In fact, it does not even try to infer the type of a variable (4.1) or property (4.2) ?eld unless it has a direct initialization. 也有一些情況遞歸調用，當類型推斷有限制的時候。如果一個函數遞歸調用它自身，它的類型還不（完全）不知道，類型推斷可能推斷一個錯誤，太詳細的類型。 > There are also some cases involving recursion where type inference has limitations. If a function calls itself recursively while its type is not (completely) known yet, type inference may infer a wrong, too specialized type. 一種不同類型的限制涉及代碼的可讀性。如果類型推斷過度使用，可能由于可見類型的缺失而難于理解程序的部分。特別是在方法簽名。建議在類型推斷和顯式類型中找到一個好的平衡。 > A different kind of limitation involves the readability of code. If type inference is overused it might be dif?cult to understand parts of a program due to the lack of visible types. This is particularly true for method signatures. It is recommended to ?nd a good balance between type inference and explicit type hints.