JavaScript Practice Lesson 12 of 21

Roman numeral converter

Roman numerals map cleanly onto a lookup table plus greedy subtraction: pair every symbol with its numeric value, walk the table from biggest to smallest, and for each pair keep subtracting the value (and appending the symbol) for as long as the remaining number is big enough.

The only wrinkle is the subtractive cases - 4 is "IV", not "IIII", and 9 is "IX", not "VIIII". The clean fix is to put those combined symbols right in the table alongside the plain ones (90 -> "XC", 40 -> "XL", 9 -> "IX", 4 -> "IV"), in order from largest to smallest. The same greedy loop handles them automatically - no special-casing needed.

Your task: write toRoman(n) for n from 1 to 100, converting n to its roman numeral string.

You'll practice:

Building and walking a lookup table in priority order
Greedy subtraction to consume a number down to zero

// Write toRoman(n): convert a number (1-100) to a roman numeral string.
// e.g. toRoman(9) === "IX", toRoman(58) === "LVIII"
function toRoman(n) {

}