【PHP】クラス内に定数constを定義してEnum（列挙型）のように使う

class TestEnum
{
    const January = 1;
    const February = 2;
    const March = 3;
    const April = 4;
    const May = 5;
    const Jun = 6;
    const July = 7;
    const August = 8;
    const September = 9;
    const October = 10;
    const November = 11;
    const December = 12;
}
echo TestEnum::February . PHP_EOL;                                                                                      
echo TestEnum::December . PHP_EOL;

2
12