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[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    int a, b, number, logNum, nThNum;

    NSLog(@"Please enter a valid integer: ");
    scanf("%d", &number); // read input as a decimal integer

    if (!number) // if zero or something other than a number is entered output zero
        NSLog(@"Zero");
    else if (number < 0) { // convert negatives to something that can be used
        number = -number;
        NSLog(@"(negative)"); // but output negative first then continue as usual
    }

    logNum = (log10(number) + 1); // find how many digits there are in the number

    for (int j=0; j < logNum; j++) {// loop based on number of digits
        a = pow(10,logNum-j);
        b = pow(10,logNum-1-j);
        nThNum = (number % a) / b;// find the nth digit in a number, in our case 1st
        switch (nThNum) {// output current digit that was found
            case 0:
                NSLog(@"Zero");
                break;
            case 1:
                NSLog(@"One");
                break;
            case 2:
                NSLog(@"Two");
                break;
            case 3:
                NSLog(@"Three");
                break;
            case 4:
                NSLog(@"Four");
                break;
            case 5:
                NSLog(@"Five");
                break;
            case 6:
                NSLog(@"Six");
                break;
            case 7:
                NSLog(@"Seven");
                break;
            case 8:
                NSLog(@"Eight");
                break;
            case 9:
                NSLog(@"Nine");
                break;
            default:
                break;
        }
    }

    [pool drain];
    return 0;
}

Well, now that you've posted your code, your method will work great if you first reverse the number. So, you can just write a short routine to do that, then use your own code.

Answer 2

This isn't exactly what you want, but for your consideration:

NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterSpellOutStyle];

NSString *s = [f stringFromNumber:[NSNumber numberWithInt:932]];
NSLog(@"%@", s);
[f release];

This will log:

nine hundred and thirty-two

Again, it's not the "nine three two" you want, but it's also nice and short. :)

Answer 3

very easy, there are number of approaches but i normally try this :

  do
    {
         digit = number % 10;
        switch (digit) {
            case 0:
                [self prependNumber:@"zero"];
                break;
            case 1:
                [self prependNumber:@"one"];
                break;
            case 2:
                [self prependNumber:@"two"];
                break;
            case 3:
                [self prependNumber:@"three"];
                break;
            case 4:
                [self prependNumber:@"four"];
                break;
            case 5:
                [self prependNumber:@"five"];
                break;
            case 6:
                [self prependNumber:@"six"];
                break;
            case 7:
                [self prependNumber:@"seven"];
                break;
            case 8:
                [self prependNumber:@"eight"];
                break;
            case 9:
                [self prependNumber:@"nine"];
                break;
            default:
                break;
        }


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

/************/
-(void) prependNumber:(NSString*)str{
 NSLog(str);
}

Answer 4

As a learning exercise, I modified Dave's code:

+(NSString*)doIt:(NSString*)inString delimiter:(NSString*)delimiter{
    NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
    [f setNumberStyle:NSNumberFormatterSpellOutStyle];
    NSMutableString* outString= [[NSMutableString alloc]init];
    for (int i=0; i< [inString length]; i++) {
        unsigned char oneChar= [inString characterAtIndex:i];
        if (oneChar>47 && oneChar<58) {
            NSString* temp=[f stringFromNumber:[NSNumber numberWithUnsignedChar:oneChar-48]];
            [outString appendFormat:@"%@",temp];
            [outString appendString:delimiter];
        }
    }
    [f release];
    [outString autorelease];
    return outString;
}

Answer 5

I use nested under nested loop but believe that this works

    int i, j, number, reversenumber = 0;

    NSLog(@" Input Number:");
    scanf( "%i", &number);

    if (number != 0)
        // chekcing for zero entry
    {
        for (;number!= 0; number = number/10)
            //for reversing the number entered so that the words doesn't come reversed when printed
        {
            i = number%10;
            reversenumber = reversenumber * 10 + i;
        }

        NSLog(@"Reverser Number for the input number is %i", reversenumber);
        // mid routine check to print the reversed number

        while(reversenumber != 0)
        {
            j = reversenumber % 10;
            switch (j)
            {
                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;
                default:
                    NSLog(@"zero");
            }
            reversenumber /= 10;
        }

    }
    else
        NSLog(@"Zero");
}

    return 0;

}

Answer 6

Well it sounds like you're halfway there if you were able to get the numbers to convert to words already, even if output backwards.

Assuming you're looping through your data, incrementing the index, just start at the character length of the number, decrementing your index backwards, reversing your output.

We can't help you much more without seeing your actual code. ;)