nested functions in php throws an exception when the outer is called more than once

Question

lest assume that i have the following

function a(){
  function b(){}
}
a(); //pass
a(); //error

why in the second call an exception is thr

Answer 1

It's exactly what is says, when you call a() again it tries to redeclare b(), declare b() outside of a() and call b() from within a() like so:

function a() {
  b();
}

function b() {}

a();
a();