iOS上的Objective-C类型


147

我想问一下iOS上的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。因此在示例中:short int-2个字节-有符号:-32768至32767和无符号:0至65535这仅是示例。


Objective-C是C之上的薄层,这意味着您具有与相同的基本数据类型C
心教堂

Answers:


349

这是一个很好的概述:

http://reference.jumpingmonkey.org/programming_languages/objective-c/types.html

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

在iPhone 3GS上运行时(iPod Touch和较旧的iPhone应该产生相同的结果),您会得到:

Primitive sizes:
The size of a char is: 1.                
The size of short is: 2.                 
The size of int is: 4.                   
The size of long is: 4.                  
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: 4.         
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:   -2147483648                  
LONG_MAX:   2147483647                   
ULONG_MAX:  4294967295                   
LLONG_MIN:  -9223372036854775808         
LLONG_MAX:  9223372036854775807          
ULLONG_MAX: 18446744073709551615 

64位进程:

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

6
请注意,随着iOS 7 SDK的发布,某些类型在64位模式下会更大。
JeremyP

13
更新了64位进程
jjxtra 2013年

很棒的答案真的很有帮助。有趣的是,在Swift中,您只需要声明一个“ var”并将其保留在那哈哈:)

1
为什么在64位处理器中int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。也许是为了向后兼容或遗留...。我不知道。有人知道原因吗?
里卡多2015年

1
UINT_MAX在哪里?
codehearted

20

请注意,您还可以在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

维基百科页面有什么在这个头可如果你没有C标准的副本(你应该,不过,因为Objective-C的是C的只是一个很小的扩展名)一个体面的描述。您可能还会发现标头,limits.h并且inttypes.h很有用。


还有SInt32,UInt32等(在Core Audio中使用很多)。
Nicolas Miari 2014年

12

更新新的64位架构

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
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