初心者が進めるiphoneアプリ開発

戻り値「return」でオブジェクトのポインタを返したりします。

//返り値なし
- (IBAction)returntest{
    [self test1];
}

- (void)test1{
    display.text=@"test1";
}

実行結果

//intの戻り
- (IBAction)returntest{
    int i;
    i=[self test1];
    display.text=[NSString stringWithFormat:@"%d",i];
}

- (int)test1{
    return 99;
}

実行結果

//NSStringの戻り
- (IBAction)returntest{
    NSString *str;
    str=[self test1];
    display.text=str;
}

//返り値
- (NSString *)test1{
    return [NSString stringWithFormat:@"戻り値"];
}

実行結果

//NSArrayの戻り
- (IBAction)returntest{
    NSArray *ar;
    ar=[self test1];
    NSLog([ar objectAtIndex:0]);
    NSLog([ar objectAtIndex:1]);
    NSLog([ar objectAtIndex:2]);
}

- (NSArray *)test1{
    NSArray *testarr;
    testarr=[NSArray arrayWithObjects:@"a",@"b",@"c",nil];
    return testarr;	
}

実行結果

//NSMutableArrayの戻り
- (IBAction)returntest{
    NSMutableArray *mar=[[NSMutableArray alloc]initWithCapacity:0];
    mar=[self test1];
    NSLog([[mar objectAtIndex:0] objectAtIndex:0]);
    NSLog([[mar objectAtIndex:0] objectAtIndex:1]);
    NSLog([[mar objectAtIndex:0] objectAtIndex:2]);
    NSLog([[mar objectAtIndex:1] objectAtIndex:0]);
    NSLog([[mar objectAtIndex:1] objectAtIndex:1]);
    NSLog([[mar objectAtIndex:1] objectAtIndex:2]);
    NSLog([[mar objectAtIndex:2] objectAtIndex:0]);
    NSLog([[mar objectAtIndex:2] objectAtIndex:1]);
    NSLog([[mar objectAtIndex:2] objectAtIndex:2]);
}

- (NSMutableArray *)test1{
    NSArray *testarr;
    NSArray *testarr2;
    NSArray *testarr3;
    NSMutableArray *aryRet=[[NSMutableArray alloc]initWithCapacity:0];
    
    testarr=[NSArray arrayWithObjects:@"a",@"b",@"c",nil];
    testarr2=[NSArray arrayWithObjects:@"A",@"B",@"C",nil];
    testarr3=[NSArray arrayWithObjects:@"あ",@"い",@"う",nil];
    [aryRet addObject:testarr];
    [aryRet addObject:testarr2];
    [aryRet addObject:testarr3];
    
    return aryRet;
}

実行結果