how can we know last digit of number in js code example

Example: How to get last digit of a number in words (javascript)

function main(englishName) {
    var data = {
        '1': 'one',
        '2': 'two',
        '3': 'three',
        '4': 'four',
        '5': 'five',
        '6': 'six',
        '7': 'seven',
        '8': 'eight',
        '9': 'nine'
    }

    var number = englishName;
    var lastNum = number.toString().split('').pop()

    console.log(data[lastNum])
}