javascripr implementation of convert integer to roman

convertToRoman.js

const convertToRoman = num => {
    const numbers = {
        "1X": "I",
        "1V": "V",
        "2X": "X",
        "2V": "L",
        "3X": "C",
        "3V": "D",
        "4X": "M"
    }

    const numString = num.toString()
    const digitsRom = []
    for (let i = 0; i < numString.length; i++) {
        const digit = numString.length - i
        const symbols = {
            1: numbers[digit + "X"],
            5: numbers[digit + "V"],
            10: numbers[digit + 1 + "X"]
        }
        const digitInt = +numString[i]
        if (digitInt <= 0) {
            digitsRom.push("")
        } else if (digitInt < 4) {
            let n = ""
            for (let i = 0; i < digitInt; i++) {
                n += symbols[1]
            }
            digitsRom.push(n)
        } else if (digitInt === 4) {
            digitsRom.push(symbols[1] + symbols[5])
        } else if (digitInt === 5) {
            digitsRom.push(symbols[5])
        } else if (digitInt < 9) {
            let n = symbols[5]
            for (let i = 5; i < digitInt; i++) {
                n += symbols[1]
            }
            digitsRom.push(n)
        } else {
            digitsRom.push(symbols[1] + symbols[10])
        }
    
    }

    return digitsRom.join("")
}

console.log(convertToRoman(905));