Why are there static properties
Just for convenience, you can use the methods inside without instantiating a class
code practice
class math{
static public function add（$a,$b){
return $a+$b;
}
}
$sum = new math();
$sum -> add(2,3);
The return result of this writing is 5
But you can also do not need to instantiate this class, you need to add static before the method
Use the trick math::add(2,3) without instantiating this class
class constant call
define('PI',3.1415926);
class math{
public function addc(){
echo PI; //The call is a global constant
}
}
$bb = new math();
$bb->addc();
So the problem is that if I need to call the constants in the class, I need to write like this
class math{
const PI = 3.1415926;
public function addc（）{
echo math::PI;
}
}
$bb = new math();
$bb -> addc();