Cleanup function which puts age in age group bucket - possible?

Question

I have this function which categorizes the age of a user in a certain age group:

private function calculateAgeGroup($age)
{
    if (!$age) {
        return null;
    }

    if ($age <= 25) {
        return '0-25';
    }

    if ($age <= 30) {
        return '26-30';
    }

    if ($age <= 35) {
        return '31-35';
    }

    if ($age <= 40) {
        return '36-40';
    }

    if ($age <= 45) {
        return '41-45';
    }

    if ($age <= 50) {
        return '46-50';
    }

    if ($age <= 60) {
        return '51-60';
    }

    return '61-';
}

Is there a way to simplify (meaning: less verbose, less if statements) this? My first thought was about using modulo, but I dismissed that very fast as it just doesn't make sense to use modulo here.

Second option would be something like floor($age/10)*10 . "-" . ceil($age/10)*10 but that also doesn't work in all cases.

The last option which came to my mind would be using a series of () ? : statements which would make for shorter but NOT more readable code. Also not so good.

Anyone has any good idea how to simplify this? Suggestions appreciated.

Answer 1

Try this code:

function calculateAgeGroup($age) {
    switch($age) {
    case $age <= 25:
        return '0-25';
        break;
    case $age > 50 && $age <= 60:
        return '51-60';
        break;
    case $age > 60:
        return '61-';
        break;
    default:
        return (floor(($age-1)/5)*5+1) . "-" . ceil($age/5)*5;
    }
}