iOS上Objective-C中的类型
我想问一下iOS上Objective-C中的基本数据类型 我需要表示变量的大小和变量的范围。 例如: 短整数-2字节-有符号:-32768到32767,无符号:0到65535iOS上Objective-C中的类型,ios,objective-c,Ios,Objective C,我想问一下iOS上Objective-C中的基本数据类型 我需要表示变量的大小和变量的范围。 例如: 短整数-2字节-有符号:-32768到32767,无符号:0到65535 这只是一个例子。这是一个很好的概述: 或运行以下代码: 32位进程: NSLog(@"Primitive sizes:"); NSLog(@"The size of a char is: %d.", sizeof(char)); NSLog(@"The size of short is: %d.", size
这只是一个例子。这是一个很好的概述: 或运行以下代码: 32位进程:
NSLog(@"Primitive sizes:");
NSLog(@"The size of a char is: %d.", sizeof(char));
NSLog(@"The size of short is: %d.", sizeof(short));
NSLog(@"The size of int is: %d.", sizeof(int));
NSLog(@"The size of long is: %d.", sizeof(long));
NSLog(@"The size of long long is: %d.", sizeof(long long));
NSLog(@"The size of a unsigned char is: %d.", sizeof(unsigned char));
NSLog(@"The size of unsigned short is: %d.", sizeof(unsigned short));
NSLog(@"The size of unsigned int is: %d.", sizeof(unsigned int));
NSLog(@"The size of unsigned long is: %d.", sizeof(unsigned long));
NSLog(@"The size of unsigned long long is: %d.", sizeof(unsigned long long));
NSLog(@"The size of a float is: %d.", sizeof(float));
NSLog(@"The size of a double is %d.", sizeof(double));
NSLog(@"Ranges:");
NSLog(@"CHAR_MIN: %c", CHAR_MIN);
NSLog(@"CHAR_MAX: %c", CHAR_MAX);
NSLog(@"SHRT_MIN: %hi", SHRT_MIN); // signed short int
NSLog(@"SHRT_MAX: %hi", SHRT_MAX);
NSLog(@"INT_MIN: %i", INT_MIN);
NSLog(@"INT_MAX: %i", INT_MAX);
NSLog(@"LONG_MIN: %li", LONG_MIN); // signed long int
NSLog(@"LONG_MAX: %li", LONG_MAX);
NSLog(@"ULONG_MAX: %lu", ULONG_MAX); // unsigned long int
NSLog(@"LLONG_MIN: %lli", LLONG_MIN); // signed long long int
NSLog(@"LLONG_MAX: %lli", LLONG_MAX);
NSLog(@"ULLONG_MAX: %llu", ULLONG_MAX); // unsigned long long int
The size of a char is: 1.
The size of short is: 2.
The size of int is: 4.
The size of long is: 8.
The size of long long is: 8.
The size of a unsigned char is: 1.
The size of unsigned short is: 2.
The size of unsigned int is: 4.
The size of unsigned long is: 8.
The size of unsigned long long is: 8.
The size of a float is: 4.
The size of a double is 8.
Ranges:
CHAR_MIN: -128
CHAR_MAX: 127
SHRT_MIN: -32768
SHRT_MAX: 32767
INT_MIN: -2147483648
INT_MAX: 2147483647
LONG_MIN: -9223372036854775808
LONG_MAX: 9223372036854775807
ULONG_MAX: 18446744073709551615
LLONG_MIN: -9223372036854775808
LLONG_MAX: 9223372036854775807
ULLONG_MAX: 18446744073709551615
在iPhone 3GS上运行时(iPod Touch和旧款iPhone应该会产生相同的结果),您会得到:
64位进程:
NSLog(@"Primitive sizes:");
NSLog(@"The size of a char is: %d.", sizeof(char));
NSLog(@"The size of short is: %d.", sizeof(short));
NSLog(@"The size of int is: %d.", sizeof(int));
NSLog(@"The size of long is: %d.", sizeof(long));
NSLog(@"The size of long long is: %d.", sizeof(long long));
NSLog(@"The size of a unsigned char is: %d.", sizeof(unsigned char));
NSLog(@"The size of unsigned short is: %d.", sizeof(unsigned short));
NSLog(@"The size of unsigned int is: %d.", sizeof(unsigned int));
NSLog(@"The size of unsigned long is: %d.", sizeof(unsigned long));
NSLog(@"The size of unsigned long long is: %d.", sizeof(unsigned long long));
NSLog(@"The size of a float is: %d.", sizeof(float));
NSLog(@"The size of a double is %d.", sizeof(double));
NSLog(@"Ranges:");
NSLog(@"CHAR_MIN: %c", CHAR_MIN);
NSLog(@"CHAR_MAX: %c", CHAR_MAX);
NSLog(@"SHRT_MIN: %hi", SHRT_MIN); // signed short int
NSLog(@"SHRT_MAX: %hi", SHRT_MAX);
NSLog(@"INT_MIN: %i", INT_MIN);
NSLog(@"INT_MAX: %i", INT_MAX);
NSLog(@"LONG_MIN: %li", LONG_MIN); // signed long int
NSLog(@"LONG_MAX: %li", LONG_MAX);
NSLog(@"ULONG_MAX: %lu", ULONG_MAX); // unsigned long int
NSLog(@"LLONG_MIN: %lli", LLONG_MIN); // signed long long int
NSLog(@"LLONG_MAX: %lli", LLONG_MAX);
NSLog(@"ULLONG_MAX: %llu", ULLONG_MAX); // unsigned long long int
The size of a char is: 1.
The size of short is: 2.
The size of int is: 4.
The size of long is: 8.
The size of long long is: 8.
The size of a unsigned char is: 1.
The size of unsigned short is: 2.
The size of unsigned int is: 4.
The size of unsigned long is: 8.
The size of unsigned long long is: 8.
The size of a float is: 4.
The size of a double is 8.
Ranges:
CHAR_MIN: -128
CHAR_MAX: 127
SHRT_MIN: -32768
SHRT_MAX: 32767
INT_MIN: -2147483648
INT_MAX: 2147483647
LONG_MIN: -9223372036854775808
LONG_MAX: 9223372036854775807
ULONG_MAX: 18446744073709551615
LLONG_MIN: -9223372036854775808
LLONG_MAX: 9223372036854775807
ULLONG_MAX: 18446744073709551615
请注意,您也可以在Objective-C中很好地使用C99固定宽度类型:
#import <stdint.h>
...
int32_t x; // guaranteed to be 32 bits on any platform
#导入
...
int32_t x;//在任何平台上保证为32位
如果您没有C标准的副本,那么这个标题中有一个很好的描述(但是您应该这样做,因为Objective-C只是C的一个很小的扩展)。您还可能会发现标题
limits.h
和inttypes.h
非常有用。更新新的64位arch
Ranges:
CHAR_MIN: -128
CHAR_MAX: 127
SHRT_MIN: -32768
SHRT_MAX: 32767
INT_MIN: -2147483648
INT_MAX: 2147483647
LONG_MIN: -9223372036854775808
LONG_MAX: 9223372036854775807
ULONG_MAX: 18446744073709551615
LLONG_MIN: -9223372036854775808
LLONG_MAX: 9223372036854775807
ULLONG_MAX: 18446744073709551615
请注意,随着iOS 7 SDK的发布,某些类型在64位模式下会更大。针对64位处理器进行更新非常有用。有趣的是,在Swift中,你只需声明一个“var”就可以了,哈哈:)为什么int在64位处理器中是32位?我看到A7 iphone处理器中有一个叫做LP64的东西,但我不明白原因。可能是为了向后兼容或遗留问题。。。。我不知道。有人知道原因吗?UINT_MAX在哪里?还有SInt32、UInt32等(在核心音频中大量使用),这意味着您得到的基本数据类型与。