Can I include a function inside of another functio

问题:

Is it possible to include one function inside another? To learn functions, I'm trying to create a combat sequence using PHP. The sequence would look like this:

1. Dice would roll, assigning numbers to variables;
2. Hero1 attack results are printed;
3. Dice would roll, assigning numbers to variables;
4. Hereo2 attack results are printed;
5. Dice would roll, assigning numbers to variables;
6. Hero3 attack results are printed.

The dice rolling would be an automated function. Here is the code:

<?
rollSim();
combatSim();

function rollSim() {
    $hAttack = rand(1,20);
    $mDefend = rand(1,20);
    $mAttack = rand(1,20);
    $hDefend = rand(1,20);
    $mDamage = rand(10,25);
    $hDamage = rand(1,20);
} // end rollSim

function combatSim() {
    rollSim();
    if ($hAttack>$mDefend) {
        print "Hero hit monster for $hDamage damage.<br>";
    } else if ($hAttack<=$mDefend) {
        print "Hero missed monster.";
    }
} // end combatSim

?>

回答1:

Your rollSim() function should return the rolled numbers rather than setting some variables and trying to use them in your other function. I would return them in an associative array, like this:

function rollSim() {
    $roll['hAttack'] = rand(1,20);
    $roll['mDefend'] = rand(1,20);
    $roll['mAttack'] = rand(1,20);
    $roll['hDefend'] = rand(1,20);
    $roll['mDamage'] = rand(10,25);
    $roll['hDamage'] = rand(1,20);

    return $roll;
}

function combatSim() {
    $roll = rollSim();

    if ($roll['hAttack'] > $roll['mDefend']) {
        print "Hero hit monster for {$roll['hDamage']} damage.<br>";
    } else if ($roll['hAttack'] <= $roll['mDefend']) {
        print "Hero missed monster.";
    }
}

回答2:

No, you can't really do what you're asking. Even if you embedded the declaration of rollSim() inside the definition of combatSim() (which you can do, that's legal but has no real effects), the variables you're setting in rollSim() would still be local to it and inaccessible by combatSim().

You need a better way of passing around the information you're concerned with. Jeremy Ruten details a good way. Another way would be to define an object that's responsible for modeling your combat event and have rollSim() and combatSim() both be methods on it.

class myCombat {

    private $hAttack;
    private $mDefend;
    private $mAttack;
    private $hDefend;
    private $mDamage;
    private $hDamage;

    function rollSim() {
        $this->hAttack = rand(1, 20);
        $this->mDefend = rand(1, 20);
        $this->mAttack = rand(1, 20);
        $this->hDefend = rand(1, 20);
        $this->mDamage = rand(10, 25);
        $this->hDamage = rand(1, 20);
    }

    function combatSim() {
        $this->rollSim();
        if($this->hAttack > $this->mDefend)
            echo 'Hero hit monster for ' . $this->hDamage . ' damage.<br />';
        else
            echo 'Hero missed monster';
    }

}

$combat = new myCombat;
$combat->combatSim();

回答3:

You can call functions from one another, certainly... but I think you want to use the scope of one in another, correct?

Sharing scope is a messy business. You're better off passing arguments.

回答4:

If you want to define functions within function in PHP you can do it like this:

function a()
{
    function b()
    {
        echo 'I am b';
    }
    function c()
    {
        echo 'I am c';
    }
}
a();
b();
c();

You must call the parent function first, then the functions inside.

回答5:

here is the simple example call function within function

class Percobaan{

  public function coba(){
    return "return value";
  }

  public function call(){
    //call coba function
    return $this->coba();
  }

} // end of class percobaan

//call the method
$klass = new Percobaan();
echo $klass->call();

the output willbe :

"return value"

回答6:

That would be a closure if you would.