Replacing characters in an NSString after converting an NSDictionary to an NSString - ios

Question

I've searched around and couldn't find an answer, so forgive me if I've created a duplicate question.
I've converted an NSDictionary into an NSString and would like to take out all the occurrences of "{", "}", and ";". When I use stringByReplacingOccurrencesOfString nothing appears different in the NSLog.
The code I've written:
NSString *myString = [myDictionary description];
[myString stringByReplacingOccurrencesOfString: #"{" withString:#""];
[myString stringByReplacingOccurrencesOfString: #"}" withString:#""];
[myString stringByReplacingOccurrencesOfString: #";" withString:#""];
NSLog(#"%#", myString);

Answer 1

The reason that nothing appears different is that the stringByReplacingOccurencesOfString returns a new string that you need to assign to myString, it doesn't mutate the string in place, so you could use
NSString *myString = [myDictionary description];
myString=[myString stringByReplacingOccurrencesOfString: #"{" withString:#""];
myString=[myString stringByReplacingOccurrencesOfString: #"}" withString:#""];
myString=[myString stringByReplacingOccurrencesOfString: #";" withString:#""];
NSLog(#"%#", myString);
But, generally the use of description for anything other that debugging/logging should be avoided. You should iterate the dictionary directly - For example.
NSMutableString *myString=[NSMutableString new];
for (NSString *key in myDictionary.allKeys) {
[myString appendString:#"%# = %#\r\n",key,myDictionary[key]];
}
NSLog(#"%#",myString");

Answer 2

You need to use stringByTrimmingCharactersInSet and stringByReplacingOccurrencesOfString api both. Refer the below sample code:-
NSString *myString = [myDictionary description];
NSString *str=[myString stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#"{}"]];
NSLog(#"%#", [str stringByReplacingOccurrencesOfString:#";" withString:#""]);