比较两个数组并设置if否则

Question

I need to compare two arrays (A & B), than for the elements of A that belong also to BI need to set an if statement. Just to explain me better:

if (elementOfArrayA belong AlsoToarrayB) {
        //do something
    }else{
        //do something else
    }

Someone could help me? Thanks

Answer 1

NSArray has an instance method called containsObject: exactly for this.

For further clarification, check this out.

Answer 2

Use following code to compare two array :

    NSArray *array1 = [[NSArray alloc] initWithObjects:@"a",@"b",@"c",nil];
    NSArray *array2 = [[NSArray alloc] initWithObjects:@"a",@"d",@"c",nil];

     for(int i = 0;i<[array1 count];i++)
        {
            for(int j= 0;j<[array2 count];j++)
            {
                if([[array1 objectAtIndex:i] isEqualToString:[array2 objectAtIndex:j]])
                {

                }  else {

                }
            }
        }

Answer 3

Comparing two arrays:

if([arrayA isEqualToArray:arrayB]){
//the two arrays A and B are equals
}

The code above will test ALL elements of both arrays to check if they fulfill the isEqual test, so no need to for loop the array.

If you want to check wether an element of arrayA is contained in arrayB, use the following method:

id firstCommonObject = [arrayA firstObjectCommonWithArray:arrayB];

if(firstCommonObject != nil){
  //a common object between arrayA and arrayB has been found

}else{
  //no common objects between both arrays
}

Answer 4

// Method 1 - Simplest method to solve above problem (Use NSArray's containsObject method)
NSArray *array1 = [[NSArray alloc] initWithObjects:@"a",@"b",@"c",@"e", nil];
NSArray *array2 = [[NSArray alloc] initWithObjects:@"a",@"d",@"c",@"f", nil];

for(id i in array1){
    if ([array2 containsObject:i]) {
        // do something
    }
    else {
        // do something else
    }
}

// Method 2 - Another method (Use NSString's isEqualToString method)
NSArray *array1 = [[NSArray alloc] initWithObjects:@"a",@"b",@"c",@"e", nil];
NSArray *array2 = [[NSArray alloc] initWithObjects:@"a",@"d",@"c",@"f", nil];

for(id i in array1){
    for(id j in array2){
        if ([i isEqualToString:j]) {
            // do something
        }
        else {
            //do something else
        }
    }
}

Answer 5

it may be help you...

-(void)methodFour
{
    NSArray *arr1 = [[NSArray alloc]initWithObjects:@"a2223a",@"ab33b",@"a1acdf",@"ac23c45", nil];
    NSArray *arr11 =  [arr1 sortedArrayUsingSelector:@selector(localizedCompare:)];
    NSLog(@"%@",arr11);

    NSArray *arr2 = [[NSArray alloc]initWithObjects:@"ab33b",@"ac23c45",@"a1acdf",@"a2223a", nil];
    NSArray *arr22= [arr2 sortedArrayUsingSelector:@selector(localizedCompare:)];
    [self firstArray:arr11 secondArray:arr22];
   }
-(void)firstArray:(NSArray *)array1 secondArray:(NSArray *)array2
{
    if ([array1 isEqualToArray:array2])
    {
        NSLog(@"equal");

    }
    else
    {
        NSLog(@"Not equal");

    }
}