iOS 上 Objective-C 中的类型 [英] Types in Objective-C on iOS

问题描述

我想问一下 iOS 上 Objective-C 中的基本数据类型.

I want to ask about the fundamental data types in Objective-C on iOS.

我需要表示变量的大小和变量的范围.所以在例子中:short int - 2 个字节 - 有符号:-32768 到 32767 和无符号:0 到 65535这只是一个例子.

I need the size on which the variable is represented and the range of the variable. So in example: short int - 2 bytes - signed: -32768 to 32767 and unsigned: 0 to 65535 This is only an example.

推荐答案

这是一个很好的概述:

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

或运行此代码:

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 和旧款 iPhone 应该产生相同的结果)，您会得到:

When run on an iPhone 3GS (iPod Touch and older iPhones should yield the same result) you get:

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

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