比较两个数组并将相等的对象放入一个新数组中

时间:2011-08-29 10:44:08

标签: objective-c cocoa cocoa-touch collections nsarray

如何比较两个NSArray并将相等的对象放入新数组?

3 个答案:

答案 0 :(得分:6)

NSArray *array1 = [[NSArray alloc] initWithObjects:@"a",@"b",@"c",nil];
    NSArray *array2 = [[NSArray alloc] initWithObjects:@"a",@"d",@"c",nil];
    NSMutableArray *ary_result = [[NSMutableArray alloc] init];
    for(int i = 0;i<[array1 count];i++)
    {
        for(int j= 0;j<[array2 count];j++)
        {
            if([[array1 objectAtIndex:i] isEqualToString:[array2 objectAtIndex:j]])
            {
                [ary_result addObject:[array1 objectAtIndex:i]];
                break;
            }
        }
    }
    NSLog(@"%@",ary_result);//it will print a,c

答案 1 :(得分:2)

答案:

NSArray *firstArr, *secondArr;
// init arrays here
NSMutableArray *intersection = [NSMutableArray array];
for (id firstEl in firstArr)
{
    for (id secondEl in secondArr)
    {
        if (firstEl == secondEl) [intersection addObject:secondEl];
    }
}
// intersection contains equal objects

将使用方法compare:比较对象。如果您想使用其他方法,只需将if (firstEl == secondEl)替换为 yourComparator ,它将向相同的对象返回YES:if ([firstEl yourComparator:secondEl])

答案 2 :(得分:1)

//i assume u have first and second array with objects

//NSMutableArray *first = [ [ NSMutableArray alloc]init];

//NSMutableArray *second = [ [ NSMutableArray alloc]init];                             

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


    for (id obj in first) {

        if ([second  containsObject:obj] ) {


            [third addObject:obj];

        }


    }


NSLog(@"third is : %@ \n\n",third);


more over if u have strings in both array then look at this answer of mine

Finding Intersection of NSMutableArrays