在PHP中堆叠多个三元运算符

This is what I wrote :

这就是我写的：

 $Myprovince = (
($province == 6) ? "city-1" :
($province == 7) ? "city-2" :
($province == 8) ? "city-3" :
($province == 30) ? "city-4" : "out of borders"
);
 $Myprovince