Question

I have an NSDictionary with NSStrings

Some of the valueForKey:@”Key” have no entry so it’s (null)

NSMutableString* addressDictionaryToString = [NSMutableString string];  // use mutable string!
for (NSDictionary* item in address) {     // use fast enumeration!
        [addressDictionaryToString appendFormat:@"%@, %@, %@, %@",
         [item objectForKey:@"Street"],         
         [item objectForKey:@"City"],
         [item objectForKey:@"State"],
         [item objectForKey:@"ZIP"]
         ];
    NSLog(@"MutableString: %@", addressDictionaryToString);
}

So I want to build an NSMutableString but filter out those keys that are null. Any ideas?

UPDATE:::::

Basically I want my resulting String to look like

1 Infinite Loop, Cupertino, CA, 95014 (IF all fields are available)

If Im missing the Street then

Cupertino, CA, 95014

If I’m missing the State then

1 Infinite Loop, Cupertino, 95014

If I only have the state then it should print

CA

(notice that there are no commas on the last element)

Answer 1

How about checking if there’s a value for the key?

NSMutableString * addressDictionaryToString = [NSMutableString string];
for (NSDictionary * item in address)
{
    if ([item objectForKey:@"Street"])
        [addressDictionaryToString appendFormat:@"%@, ", 
         [item objectForKey:@"Street"]];
    if ([item objectForKey:@"City"])
        [addressDictionaryToString appendFormat:@"%@, ", 
         [item objectForKey:@"City"]];
    if ([item objectForKey:@"State"])
        [addressDictionaryToString appendFormat:@"%@, ", 
         [item objectForKey:@"State"]];
    if ([item objectForKey:@"ZIP"])
        [addressDictionaryToString appendFormat:@"%@, ", 
         [item objectForKey:@"ZIP"]];
    NSLog(@"MutableString: %@", addressDictionaryToString);
}

The thing is, in your last question, you said your goal was to create a CSV file. It’s not technically valid CSV if your rows have varying numbers of fields with no reliable way to identify each one.

Instead, you might try this:

NSMutableString * addressDictionaryToString = [NSMutableString string];
for (NSDictionary * item in address)
{
    [addressDictionaryToString appendFormat:@"%@,", 
     ([item objectForKey:@"Street"]) ? [item objectForKey:@"Street"] : @"" ];
    // ...
    NSLog(@"MutableString: %@", addressDictionaryToString);
}

It checks for the presence of a value and inserts that value if there is one, or just an empty string (resulting in “value,value,,value…”). Also remember there shouldn’t be a space after the comma, so I’ve removed that from this example.