#import <Foundation/Foundation.h>
@interface Caculator :NSObject
{
    @public
    int _num1;
    int _num2;
    float _result;
}
-(float)add:(int)num1 andnum2:(int) num2;
@end
@implementation Caculator
-(float)add:(int)num1 andnum2:(int) num2;
{
    //这里可以用-result = num1+ num2,然后返回的时候可以用_result返回,为什么?
    return num1+num2;

}
@end
float test(){
    Caculator *cal = [Caculator new];
    float result = [cal add:6 andnum2:2];
    NSLog(@"num1+num2=%.2f",result);
    return  .3f;
}
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        test();
    }
    return 0;
}

#import <Foundation/Foundation.h>
@interface Caculator :NSObject
{
    @public
    int _num1;
    int _num2;
    float _result;
}
-(float)add:(int)num1 andnum2:(int) num2;
@end
@implementation Caculator
-(float)add:(int)num1 andnum2:(int) num2;
{
    //这里可以用-result = num1+ num2,然后返回的时候可以用_result返回,为什么?
    return num1+num2;

}
@end
float test(){
    Caculator *cal = [Caculator new];
    float result = [cal add:6 andnum2:2];
    NSLog(@"num1+num2=%.2f",result);
    return  .3f;
}
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        test();
    }
    return 0;
}