How to split string into substrings on iOS? - ios

Question

I received an NSString from the server. Now I want to split it into the substring which I need.
How to split the string?
For example:
substring1:read from the second character to 5th character
substring2:read 10 characters from the 6th character.

Answer 1

You can also split a string by a substring, using NString's componentsSeparatedByString method.
Example from documentation:
NSString *list = #"Norman, Stanley, Fletcher";
NSArray *listItems = [list componentsSeparatedByString:#", "];

Answer 2

NSString has a few methods for this:
[myString substringToIndex:index];
[myString substringFromIndex:index];
[myString substringWithRange:range];
Check the documentation for NSString for more information.

Answer 3

I wrote a little method to split strings in a specified amount of parts.
Note that it only supports single separator characters. But I think it is an efficient way to split a NSString.
//split string into given number of parts
-(NSArray*)splitString:(NSString*)string withDelimiter:(NSString*)delimiter inParts:(int)parts{
NSMutableArray* array = [NSMutableArray array];
NSUInteger len = [string length];
unichar buffer[len+1];
//put separator in buffer
unichar separator[1];
[delimiter getCharacters:separator range:NSMakeRange(0, 1)];
[string getCharacters:buffer range:NSMakeRange(0, len)];
int startPosition = 0;
int length = 0;
for(int i = 0; i < len; i++) {
//if array is parts-1 and the character was found add it to array
if (buffer[i]==separator[0] && array.count < parts-1) {
if (length>0) {
[array addObject:[string substringWithRange:NSMakeRange(startPosition, length)]];
}
startPosition += length+1;
length = 0;
if (array.count >= parts-1) {
break;
}
}else{
length++;
}
}
//add the last part of the string to the array
[array addObject:[string substringFromIndex:startPosition]];
return array;
}