How to find a KEY from NSDictionary?

Here we will take NSMutableArray with objects and NSDictionary with Objects and Keys.

    NSMutableArray* mArray = [[NSMutableArray alloc]

                              initWithObjects:@"A",@"B",@"C",@"D",@"E",@"F", nil];

    

    NSMutableDictionary *mDic = [NSMutableDictionary

                                 dictionaryWithObjectsAndKeys:@"F",@"mF",@"G",@"mG",@"B",@"mB",@"I",@"mI",nil];

We will write a Function which can provide us the array of founded keys after comparison.

-(NSMutableArray*)compareMyObject:(NSMutableArray*)array:(NSDictionary*)dic

{

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

for(int k=0;k<[array count];k++)

{

NSString* mStr = [array objectAtIndex:k];

        NSArray* array = [dic allKeysForObject:mStr];

if([array count])

        {

            [keysArray addObject:[array objectAtIndex:0]];

        }

}

    return keysArray;

}

Now we will call this method in the following format.

    NSMutableArray* keysArray =  [self compareMyObject:mArray:mDic];

The above method gives us the result array now, We will print and check those results.

    NSLog(@"total %d keys found. Those are %@",[keysArray count],[keysArray description]);

The result is : 

keysArray = (

    mB,

    mF

)