simple example of a higher order function

higher order functions

enum SIZE {
    small = 'small',
    medium = 'medium',
    large = 'large'
}

function calculateAge(operation: Function, initialVal: number, factor: boolean | SIZE) {
    const age = operation(initialVal, factor)
    return age;
}

function computeDogAge(years: number, size: SIZE) {
    if (size === SIZE.small || size === SIZE.medium) {
        return years * 5;
    } else if (size === SIZE.large) {
        return years * 7;
    } else {
        return years * 7;
    }
}

function computePeopleAge(years: number, exercise: boolean) {
    if (exercise) {
        return years;
    } else {
        return years + 5;
    }
}

function computeCatAge(years: number, indoor: boolean) {
    if (indoor) {
        return years * 5;
    } else  {
        return years * 7;
    }
}

console.log(calculateAge(computeDogAge, 4, SIZE.medium))
console.log(calculateAge(computePeopleAge, 20, true))
console.log(calculateAge(computeCatAge, 3, true))