prog15.5.m

// Basic String Operations - Mutable Strings

#import <Foundation/Foundation.h>

int main(int argc, char *argv[])
{
  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
  NSString *str1 = @"This is a string A";
  NSString *search, *replace;
  NSMutableString *mstr;
  NSRange substr;

  // Create mutable string from nonmutable
  mstr = [NSMutableString stringWithString: str1];
  NSLog(@"%@", mstr);

  // Insert characters
  [mstr insertString: @" mutable" atIndex: 7];
  NSLog(@"%@", mstr);

  // Effective concatentation if insert at end
  [mstr insertString: @" and string B" atIndex: [mstr length]];
  NSLog(@"%@", mstr);

  // Or can user appendString directly
  [mstr appendString: @" and string c"];
  NSLog(@"%@", mstr);

  // Delete substring based on range
  [mstr deleteCharactersInRange: NSMakeRange(16,13)];
  NSLog(@"%@", mstr);

  // Find range first and then use it for deletion
  substr = [mstr rangeOfString: @"string B and "];
  if (substr.location != NSNotFound) {
    [mstr deleteCharactersInRange: substr];
    NSLog(@"%@", mstr);
  }

  // Set the mutable string directly
  [mstr setString: @"This is string A"];
  NSLog(@"%@", mstr);

  // Now let's replace a range of chars with another
  [mstr replaceCharactersInRange: NSMakeRange(8, 8) withString: @"a mutable string"];
  NSLog(@"%@", mstr);

  // Search and replace
  search = @"This is";
  replace = @"An example of";
  substr = [mstr rangeOfString: search];
  if (substr.location != NSNotFound) {
    [mstr replaceCharactersInRange: substr withString: replace];
    NSLog(@"%@", mstr);
  }

  // Search and replace all occurreces
  search = @"a";
  replace = @"X";
  substr = [mstr rangeOfString: search];
  while (substr.location != NSNotFound) {
    [mstr replaceCharactersInRange: substr withString: replace];
    substr = [mstr rangeOfString: search];
  }
  NSLog(@"%@", mstr);

  [pool drain];
  return 0;
}