2019-6: Telephone Names
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Some telephone keypads have letters of the alphabet embossed on their keytops. Some people like to remember phone numbers by converting them to an alphanumeric form using one of the letters on the corresponding key. For example, in the keypad shown, 'ALSMITH' would correspond to the number 257-6484 and '1DYALOGBEST' would correspond to 1-392-564-2378.
Write an APL function that takes a character vector right argument that consists of digits and uppercase letters and returns an integer vector of the corresponding digits on the keypad.
💡 Hint: Your solution might make use of the membership function X∊Y.
Examples:
(your_function) 'IAMYY4U'
4 2 6 9 9 4 8
(your_function) '' ⍝ should return an empty vector
(your_function) 'UR2CUTE'
8 7 2 2 8 8 3
your_function ←
Solutions
