Course of Raku / Essentials / Positional data types / Exercises / Spell a number
Solution: Spell a number
The program below has a built-in array with the names of numbers from 0 to 20 and the names of the tens: 20, 30, etc. In the chain of conditional checks, the number is distributed to one of the rules of spelling.
Code
my $n = @*ARGS[0];
my @names = <
zero one two three four five six seven eight nine ten
eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty
thirty fourty fifty sixty seventy eighty ninety >;
if $n < 20 {
say @names[$n];
}
elsif $n % 10 { # Two-digit non-round numbers, e.g., 34
say @names[$n / 10 + 18] ~ '-' ~ @names[$n % 10];
}
else { # Multiples of 10, e.g., 50
say @names[$n / 10 + 18];
}
🦋 Find the program in the file spell-a-number.raku.
Example
Run the program a few times to check all the three branches of the if—elsif—elses construction.
$ raku exercises/positionals/spell-a-number.raku 5
five
$ raku exercises/positionals/spell-a-number.raku 12
twelve
$ raku exercises/positionals/spell-a-number.raku 67
sixty-seven
$ raku exercises/positionals/spell-a-number.raku 80
eighty