Interfaces and Traits

Trait Method

A trait can contribute a reusable method to a class.

method reuse The class uses the trait method as if the method were written in the class.

Trait Method

name
trait_method.php
Replay: real traced execution (multi-file project)
<?php
trait HasLabel
{
    public function label(): string
    {
        return "tag:" . $this->name;
    }
}

class Tag
{
    use HasLabel;

    public function __construct(public string $name)
    {
    }
}

$name = "beta";
$tag = new Tag($name);
$label = $tag->label();

echo "name=" . $name . "\n";
echo "label=" . $label . "\n";

<?php
trait HasLabel
{
    public function label(): string
    {
        return "tag:" . $this->name;
    }
}

class Tag
{
    use HasLabel;

    public function __construct(public string $name)
    {
    }
}

$name = "alpha";
$tag = new Tag($name);
$label = $tag->label();

echo "name=" . $name . "\n";
echo "label=" . $label . "\n";

<?php
trait HasLabel
{
    public function label(): string
    {
        return "tag:" . $this->name;
    }
}

class Tag
{
    use HasLabel;

    public function __construct(public string $name)
    {
    }
}

$name = "stable";
$tag = new Tag($name);
$label = $tag->label();

echo "name=" . $name . "\n";
echo "label=" . $label . "\n";

  1. $name ← beta

    19$name→ beta = "beta"; //@name="alpha", "stable"20$tag = new Tag($namebeta);21$label = $tag->label();

  2. public function __construct(public string $name)

    14public function __construct(public string $namebeta)15{16}

  3. $tag ← Tag

    19$name = "beta"; //@name="alpha", "stable"20$tag→ Tag = new Tag($namebeta);21$label = $tagTag->label();

  4. public function label(): string

    3{4    public function label(): string5    {6        return "tag:" . $this->namebeta;7    }

  5. $label ← tag:beta

    20$tag = new Tag($name);21$label→ tag:beta = $tagTag->label();2223echo "name=" . $namebeta . "\n";24echo "label=" . $labeltag:beta . "\n";
    outputname=beta
label=tag:beta

  1. $name ← alpha

    19$name→ alpha = "alpha";20$tag = new Tag($namealpha);21$label = $tag->label();

  2. public function __construct(public string $name)

    14public function __construct(public string $namealpha)15{16}

  3. $tag ← Tag

    19$name = "alpha";20$tag→ Tag = new Tag($namealpha);21$label = $tagTag->label();

  4. public function label(): string

    3{4    public function label(): string5    {6        return "tag:" . $this->namealpha;7    }

  5. $label ← tag:alpha

    20$tag = new Tag($name);21$label→ tag:alpha = $tagTag->label();2223echo "name=" . $namealpha . "\n";24echo "label=" . $labeltag:alpha . "\n";
    outputname=alpha
label=tag:alpha

  1. $name ← stable

    19$name→ stable = "stable";20$tag = new Tag($namestable);21$label = $tag->label();

  2. public function __construct(public string $name)

    14public function __construct(public string $namestable)15{16}

  3. $tag ← Tag

    19$name = "stable";20$tag→ Tag = new Tag($namestable);21$label = $tagTag->label();

  4. public function label(): string

    3{4    public function label(): string5    {6        return "tag:" . $this->namestable;7    }

  5. $label ← tag:stable

    20$tag = new Tag($name);21$label→ tag:stable = $tagTag->label();2223echo "name=" . $namestable . "\n";24echo "label=" . $labeltag:stable . "\n";
    outputname=stable
label=tag:stable