This deprecation is just apple cleaning up the headers for NSDateFormatter. init is already declared in NSObject which NSNumberFormatter inherits from. Redeclaring is not necessary, however in the implementation apple will override init as subclassess should provide implementations for the default initializer of the superclass.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…