Question

我是Objective-c的新手，我遇到了一些问题。我的代码似乎检查出来，因为xcode说我没有问题，但在构建它时我说我在Molecule中的所有变量都是零。我似乎无法弄明白。让我知道如果发布我的元素类是必要的，谢谢。我愿意接受任何纠正批评并愿意学习。

这是main.m

@autoreleasepool {

    // insert code here...
    Element *myElement1 = [[Element alloc] initWithName:@"Hydrogen" andSymbol:@"H" andAtomicNumber:1 andAtomicWeight:1.00794];
    NSLog(@"The element %@ has atomic number %li.", [myElement1 name], (long)[myElement1 atomicNumber]);

    NSLog(@"The element is %@.", [myElement1 description]);

    Element *myElement2 = [[Element alloc] initWithName:@"Hydrogen" andSymbol:@"H" andAtomicNumber:1 andAtomicWeight:1.00794];

    NSLog(@"The element is %@.", [myElement2 description]);

    NSLog(@"The element %@ has atomic number %li.", [myElement2 name], (long)[myElement2 atomicNumber]);

    Element *myElement3 = [[Element alloc] initWithName:@"Oxygen" andSymbol:@"O" andAtomicNumber:8 andAtomicWeight:15.9994];

    NSLog(@"The element is %@.", [myElement3 description]);

    NSLog(@"The element %@ has atomic number %li.", [myElement3 name], (long)[myElement3 atomicNumber]);



    Molecule *myMolecule = [[Molecule alloc] initWithName:@"Water" andSymbol:@"H2O" andElement1:myElement1 andElement2:myElement2 andElement3:myElement3 andWeight:33.00674];

    NSLog(@"The molecule is %@.", [myMolecule description]);

    NSLog(@"The molecule %@ has symbol %@ and atomic number %li.", [myMolecule name], [myMolecule symbol],(long)[myMolecule weight]);



}
return 0;

}

这里是Molecule.h

@interface Molecule : NSObject{

NSString *name;
NSString *symbol;
Element *element1;
Element *element2;
Element *element3;
float weight;

}

-(id)init;
-(id)initWithName:(NSString *)newName;
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol;
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element         *)newElement1;
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element   *)newElement1 andElement2:(Element *)newElement2;
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element *)newElement1 andElement2:(Element *)newElement2 andElement3:(Element *)newElement3;
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element  *)newElement1 andElement2:(Element *)newElement2 andElement3:(Element *)newElement3 andWeight:      (float)newWeight;

-(void)setName:(NSString *)newName;
-(NSString *)name;
-(void)setSymbol:(NSString *)newSymbol;
-(NSString *)symbol;
-(void) setElement1:(Element *)newElement;
-(Element *)element1;
-(void) setElement2:(Element *)newElement;
-(Element *)element2;
-(void) setElement3:(Element *)newElement;
-(Element *)element3;
-(void)setWeight:(float) newWeight;
-(float)weight;

-(NSString *)description;

@end

这是Molecule.m

@implementation Molecule
-(id)init
{
return [self initWithName:@"No Name"];
}

-(id)initWithName:(NSString *)newName
{
    return [self initWithName:newName andSymbol:@"?"];
}

-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol
{
    return [self initWithName:newName andSymbol:newSymbol andElement1:element1];
}
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element *) newElement1
{
    return [self initWithName:newName andSymbol:newSymbol andElement1:element1 andElement2:element2];
}
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element *) newElement1 andElement2:(Element *) newElement2
{
    return [self initWithName:newName andSymbol:newSymbol andElement1:element1 andElement2:element2 andElement3:element3];
}
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element *) newElement1 andElement2:(Element *) newElement2 andElement3:(Element *)newElement3
{
    return [self initWithName:newName andSymbol:newSymbol andElement1:element1 andElement2:element2 andElement3:element3 andWeight:0.0];
}

// Designated Initializer
-(id)initWithName:(NSString *)newName andSymbol:(NSString *)newSymbol andElement1:(Element *)newElement1  andElement2:(Element *)newElement2 andElement3:(Element *)newElement3 andWeight:(float)newWeight
{
    self = [super init];
    if (self) {
        [self setName:newName];
        [self setSymbol:newSymbol];
        [self setElement1:element1];
        [self setElement2:element2];
        [self setElement3:element3];
        [self setWeight:newWeight];
    }
    return self;
}

-(void)setName:(NSString *)newName
{
    name = newName;
}
-(NSString *)name
{
    return name;
}
-(void)setSymbol:(NSString *)newSymbol
{
    symbol = newSymbol;
}
-(NSString *)symbol
{
    return symbol;
}
-(void)setElement1:(Element *)newElement1
{
    element1 = newElement1;
}
-(Element *)element1
{
    return element1;
}

-(void)setElement2:(Element *)newElement2
{
   element2 = newElement2;
}
-(Element *)element2
{
    return element2;
}
-(void)setElement3:(Element *)newElement3
{
    element3 = newElement3;
}
-(Element *)element3
{
    return element3;
}
-(void)setWeight:(float)newWeight
{
    weight = [element1 atomicWeight]+ [element2 atomicWeight]+ [element3 atomicWeight];
}
-(float)weight
{
    return weight;
}



-(NSString *)description
{
    return [NSString stringWithFormat:@"\nName : %@\nSymbol: %@\nElement1 :%@\nElement2 :%@\nElement3 : %@\nWeight : %f\n", name, symbol, element1, element2, element3, weight];
}




    @end

我的输出是：

2014-01-28 12:33:53.166 MyFirstApp[14239:303] The element Hydrogen has atomic number 1.
2014-01-28 12:33:53.168 MyFirstApp[14239:303] The element is 
Name : Hydrogen
Symbol: H
Atomic Number : 1
Atomic Weight : 1.007940
.
2014-01-28 12:33:53.168 MyFirstApp[14239:303] The element is 
Name : Hydrogen
Symbol: H
Atomic Number : 1
Atomic Weight : 1.007940
.
2014-01-28 12:33:53.168 MyFirstApp[14239:303] The element Hydrogen has atomic number 1.
2014-01-28 12:33:53.169 MyFirstApp[14239:303] The element is 
Name : Oxygen
Symbol: O
Atomic Number : 8
Atomic Weight : 15.999400
.
2014-01-28 12:33:53.169 MyFirstApp[14239:303] The element Oxygen has atomic number 8.
(lldb)

这就是变量视图中的内容

myElement2  Element *   0x10010d610 0x000000010010d610
myElement3  Element *   0x100300340 0x0000000100300340
myElement1  Element *   0x100102e90 0x0000000100102e90
myMolecule  Molecule *  nil 0x0000000000000000
NSObject    NSObject        
name    NSString *  nil 
symbol  NSString *  nil 
element1    Element *   nil 
element2    Element *   nil 
element3    Element *   nil 
weight  float

分子变量是零？

0 个答案: