完整代码示例

#import     @interface TemperatureConverter : NSObject    - (double)celsiusToFahrenheit:(double)celsiusTemperature;    - (double)fahrenheitToCelsius:(double)fahrenheitTemperature);    @end    int main(int argc, char **argv) {      NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];      // 检查命令行参数      if (argc != 3) {        NSLog(@"使用说明： %s 
     <温度> 
      <转换方向>
       \n", argv[0]);        return EXIT_FAILURE;      }      double temperature = atof(argv[1]);      NSString *direction = argv[2];      if (!direction || [direction length] != 2) {        NSLog(@"错误：转换方向必须是 'C' 或 'F'\n");        return EXIT_FAILURE;      }      double convertedTemp;      if ([direction isEqualToString:@"C"]) {        convertedTemp = [converter celsiusToFahrenheit:temperature];      } else {        convertedTemp = [converter fahrenheitToCelsius:temperature];      }      NSLog(@"转换结果： %.6f\n", convertedTemp);      [pool release];      return EXIT_SUCCESS;    }    @implementation TemperatureConverter    - (double)celsiusToFahrenheit:(double)celsiusTemperature) {      return (celsiusTemperature * 9/5) + 32;    }    - (double)fahrenheitToCelsius:(double)fahrenheitTemperature) {      return (fahrenheitTemperature - 32) * 5/9;    }    @end