Solution to roman numeral problem

Roman Numeral Problem

/**
 * @param {string} s
 * @return {number}
 */
var romanToInt = function(s) {
    romanNumerals = {
        I: 1,
        V: 5,
        X: 10,
        L: 50,
        C: 100,
        D: 500,
        M: 1000,
    }
    
    romanArr = s.split('');
     let result = 0;
    
    romanArr.forEach((numeral,i) =>{
       
        romanNum = romanNumerals[numeral];
        romanNumNext = romanNumerals[s[i+1]]
        
        if(romanNum < romanNumNext){
            result -= romanNumerals[numeral]
        }else{
            result += romanNumerals[numeral];
        }
        
    })
    return result;
};