Question

Will variable in function be destroyed after function run?

class B {
   function C() {
       $x = "123456";
       echo "XXX".$x;
       // After this function is finished, will $x be destroyed by default to save memory in PHP?
   }
}
class A {
   function F1() {
       return new Class_B();
   }

   function F2() {
       $this->F1()->C();
       // After this function is finished, will F1 be destroyed by default to save memory and CPU in PHP?
   }
}

Answer 1

Regarding $x: yes, it will be subject to garbage collection after B::C() finishes running.

Regarding $this->F1()->C(): the F1 method itself won’t be destroyed, but the instance of B returned by it will be destroyed after F2 finishes running.