How to convert numbers into text?

Question

I have been learning Objective-C with the Kochan book and I can\'t figure out how to do this exercise program. Only odd numbered exercises are listed online and this one is

Answer 1

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{

@autoreleasepool {

    // insert code here...
    int number;     //store the value the user enter
    int lastDigit;  //pick of the last digit of the integer
    int tempNum;    //a temporary storage of the integer the user enter
    int count = 0;  //used to count how many digits were entered
    int count2;     //going to be use as a duplicate of count



    NSLog(@"Enter an integer");
    scanf("%i", &number);
    tempNum = number;


    //Loop to find out how many digits were entered
    for (; number != 0; number /= 10) {
        count +=1;
        }

    //Loop to convert the numbers into words
    for (; count != 0; count -= 1) {
        count2 = count;     //set count2 to count so the for and while loop use them independently
        number = tempNum;   //restore the value entered by by the user to the number variable


        //Loop to reverse the order of the last digit

        while (count2 != 0) {           //loops to the same number of counts to get the first digit
            lastDigit = number % 10;    //picks off the last value in the integer
            number /= 10;               //enables the loop to set the last value of the integer to zero
            count2 -=1;                 //loops one less time to get the numbers from front to back

        }
        //switch statements
        switch (lastDigit) {
            case 9:
                NSLog(@"nine");
                break;
            case 8:
                NSLog(@"eight");
                break;
            case 7:
                NSLog(@"seven");
                break;
            case 6:
                NSLog(@"six");
                break;
            case 5:
                NSLog(@"five");
                break;
            case 4:
                NSLog(@"four");
                break;
            case 3:
                NSLog(@"three");
                break;
            case 2:
                NSLog(@"two");
                break;
            case 1:
                NSLog(@"one");
                break;
            case 0:
                NSLog(@"zero");
                break;
            default:
                break;
        }
    }
   }
return 0;
}

Answer 2

Since you're adding the numbers to a string, and you want to calculate them right to left, prepend the string with each new number. Something like:

numberString = [NSString stringWithFormat:@"%@ %@", theNewNumber, numberString];

Where theNewNumber is a string (like @"six") and numberString is the string that you want to output once you're done...

(oh, and don't forget to initialize numberString before you start looping...something like:

NSString *numberString = @"";

=====

Based on the code you just posted, you could either do it mathematically, or just pre-pend a string like this:

Put this variable in your .h file:

NSString *numberString;

Then put this in your .m:

- (void) prependNumber:(NSString *)num {
  numberString = [NSString stringWithFormat:@"%@ %@", num, numberString];
}

NSLog(@"Type in your integer.");
scanf("%i", &number);
numberString = @"";


 do
 {
     digit = number % 10;

     if (digit == 0)
         [self prependNumber:@"zero"];
     if (digit == 1)
         [self prependNumber:@"one"];
     if (digit == 2)
         [self prependNumber:@"two"];
     if (digit == 3)
         [self prependNumber:@"three"];
     if (digit == 4)
         [self prependNumber:@"four"];
     if (digit == 5)
         [self prependNumber:@"five"];
     if (digit == 6)
         [self prependNumber:@"six"];
     if (digit == 7)
         [self prependNumber:@"seven"];
     if (digit == 8)
         [self prependNumber:@"eight"];
     if (digit == 9)
         [self prependNumber:@"nine"];

     number /= 10;
 }
while (number != 0);

NSLog (@"%@", numberString);