如何減去數組對象？

Question

我正在開發一個應用程序，其中我需要timestamp.I有兩個數組包含小時，分鐘和秒的字符串對象，我需要減去這些並將它們放在第三個數組中，小時，分鐘和秒作爲三個對象。

例如：

arr1=[9,10,22] 
arr2=[10,12,42]; 

所以答案應該是

arr3=[1,2,22] 

，我需要把這個數組對象由' :'

好心幫分開的字符串。

Answer 1

試試這個：

NSMutableArray *arr3 = [NSMutableArray alloc]init]; 
for(int i=0;i<[arr1 count];i++) 
{ 
    [arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:i]integerValue]-[[arr1 objectAtIndex:i]integerValue]]]; 
} 

NSString *combinedStr = [arr3 componentsJoinedByString:@":"]; 

Answer 2

試試這個

NSMutableArray * arr3=[[NSMutableArray alloc]init]; 

[arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:0]integerValue]-[[arr1 objectAtIndex:0]integerValue]]]; 

[arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:1]integerValue]-[[arr1 objectAtIndex:1]integerValue]]]; 

[arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:2]integerValue]-[[arr1 objectAtIndex:2]integerValue]]]; 

Answer 3

你也可以試試這個：

NSMutableArray *arr3=[[NSMutableArray alloc]init]; 

    [arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:0]intValue]-[[arr1 objectAtIndex:0]intValue]]]; 
    [arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:1]intValue]-[[arr1 objectAtIndex:1]intValue]]]; 
    [arr3 addObject:[NSString stringWithFormat:@"%d",[[arr2 objectAtIndex:2]intValue]-[[arr1 objectAtIndex:2]intValue]]];