Iphone - How do you sort an NSMutableArray into ascending order? - nsmutablearray

Question

In Xcode i am trying to make a graph into which some points (X,Y) are given by the user.The user can choose how many points he or she wants to plot on the graph. I have stored the X axis points in an NSMutableArray and the Y axis points in an NSMutableArray but now i need to sort these into ascending order so i can fix a bug with the graph when having two points with the same x or y axis plot. The NSMutableArrays contains primitive int's. An example of what i need to do is if i am given 4 coordinates for one of the axis such as 4,8,5,3 i need the array to be sorted into 3,4,5,8
The code below doesn't include the graph generation because it is quite long
Thanks for the help! -
int userInputCount;
printf("How many coordinates would you like to plot? ");
scanf("%i", &userInputCount);
printf("\n");
NSMutableArray * xCoordArray = [[NSMutableArray alloc] init];
NSMutableArray * yCoordArray = [[NSMutableArray alloc] init];
for (int i = 1; i <= userInputCount; i++){
int xCoord;
int yCoord;
printf("(%i) Enter coordinates [X,Y]: ", i);
scanf("%i,%i", &xCoord, &yCoord);
NSNumber *xCoordinate = [[NSNumber alloc] initWithInt:xCoord];
NSNumber *yCoordinate = [[NSNumber alloc] initWithInt:yCoord];
[xCoordArray addObject:xCoordinate];
[yCoordArray addObject:yCoordinate];
}

Answer 1

After working on it for a while I figured it out if anybody is trying the same thing
for (int j = 0; j < 2; j++){
for (int i = 0; i < [yCoordArray count] - 1; i++){
int yExchangeIntOne = [[yCoordArray objectAtIndex:i] intValue];
int yExchangeIntTwo = [[yCoordArray objectAtIndex:i +1] intValue];
if (yExchangeIntOne > yExchangeIntTwo){
[yCoordArray exchangeObjectAtIndex:i+1 withObjectAtIndex:i];
i = 0;
}
int xExchangeIntOne = [[xCoordArray objectAtIndex:i] intValue];
int xExchangeIntTwo = [[xCoordArray objectAtIndex:i +1] intValue];
if (xExchangeIntOne > xExchangeIntTwo){
[xCoordArray exchangeObjectAtIndex:i+1 withObjectAtIndex:i];
i = 0;
}
}
}
This goes right after the
[xCoordArray addObject:xCoordinate]; and the
[yCoordArray addObject:yCoordinate]; in the loop