Pass function by validation function in php

Question

Good, I have a class "Entity", where I have the property "Phone", for the phone, I have a function the part that validates the phone number "isvalidTelephone", I also have a function that prints all properties... My doubt is of beginner.. How do I do instead of it simply echo the phone number, print the phone number by going through the validation of "isvalid"?

Here is my code:

GETTER AND SETTER:

public function getTelefone() {
    return $this->telefone;
}

/**
 * @param mixed $telefone
 */
public function setTelefone($telefone) {
    if ($telefone === $this->isvalidTelefone($telefone)) {
        echo "este numero esta errado";
    } else {
        echo "este numero esta certo";
    }
}

VALIDATION FUNCTION:

public function isvalidTelefone($telefone) {
    if ((strlen($telefone) < 9) || (strlen($telefone) > 9)) {
        return FALSE;
    } else {
        return TRUE;
    }
}

FUNCTION THAT PRINTS PROPERTIES:

public function printEntidade() {
    return $this->nome . '<br>' .
            $this->email . '<br>' .
            $this->nif . '<br>' .
            $this->codpostal . '<br>' .
            $this->localidade . '<br>' .
            $this->morada . '<br>' .
            $this->pais . '<br>' .
            $this->telefone . '<br>' .
            $this->saldo;
}

Thank you!

Answer 1

First valide no setTelefone and only assign the value if the isValidTelefone be it true, see below:

/**
 * @param mixed $telefone
 */
public function setTelefone($telefone)
{
    if($this->isvalidTelefone($telefone))
    {
        $this->telefone = $telefone;
    }
}

After that you can put a ternary in the function printEntidade checking whether the $this->email and concatenating if it exists, see below:

public function printEntidade()
{
    return $this->nome . '<br>' .
        $this->email . '<br>' .
        $this->nif . '<br>' .
        $this->codpostal . '<br>' .
        $this->localidade . '<br>' .
        $this->morada . '<br>' .
        $this->pais . '<br>' .
        (isset($this->telefone) ? $this->telefone . '<br>' : '') .
        $this->saldo;
}