Objective-C中int和NSInteger的区别

int是静态类型

NSInteger是动态类型

苹果官方推荐使用NSInteger，因为在苹果的api实现中，NSInteger是一个封装，它会识别当前操作系统的位数，自动返回最大的类型。

定义的代码类似于下：

#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64

typedef long NSInteger;

typedef unsigned long NSUInteger;

#else

typedef int NSInteger;

typedef unsigned int NSUInteger;

#endif

You usually want to use NSInteger when you don‘t know what kind of processor architecture your code might run on, so you may for some reason want the largest possible int type, which on 32 bit systems is just an int, while on a 64-bit system it‘s a long.