How can I convert the values is an NSDictionary into an NSString? - objective-c

Question

I have a method in Objective-c that takes in an NSDictionary and returns the values as a space-separated NSString. This application is cross-platform, and as such I cannot use fast enumeration. This is what I have so far, followed by the output (which shows that the String is never created):
-(NSString *)stringValuesFromDict:(NSDictionary *map)
{
NSArray *values = [map allValues];
NSString *params = [NSString string];
NSLog(#"values length: %d", [values count]);
NSLog(#"values = %#", [values description]);
for (int i = 0; i < [values count]; i++)
{
[params stringByAppendingString:[values objectAtIndex:i]];
[params stringByAppendingString:#" "];
}
NSLog(#"params = %#", params);
return params;
}
The NSDictionary:
{"arg1"="monkey"}
The output:
values length: 1
values = (
monkey
)
params =
What am I doing wrong? How can I get params to be set to monkey?

Answer 1

If I read the question correctly, all you need is
[[dict allValues] componentsJoinedByString:#" "]

Answer 2

You need a mutable string. Change this:
NSString *params = [NSString string];
to this:
NSMutableString *params = [NSMutableString string];
Then change these:
[params stringByAppendingString:[values objectAtIndex:i]];
[params stringByAppendingString:#" "];
to these:
[params appendString:[values objectAtIndex:i]];
[params appendString:#" "];

Answer 3

stringByAppendingString: returns a new string. So you would have to do something like this:
params = [params stringByAppendingString:[values objectAtIndex:i]];
But the disadvantage is, that every time a new string is created, which is wasting memory
You should propably use a NSMutableString instead. And then you can just call
[params appendString:[values objectAtIndex:i]];