iOS平台的App主要使用哪种语言进行开发

A.C++

B.Java

C.Python

D.Swift

A.Swift

B.Xcode

C.Java

D.Android Studio

A.Swift

B.Xcode

C.Java

D.Android Studio

A.Python

B.Golang

C.Java

D.C++

A.ifstream f(filename, ios::in| ios::app);

B.ofstream f(filename, ios::out | ios::app);

C.ofstream f(filename, ios::app);

D.fstream f(filename, ios::in | ios::out);