What is Traits in PHP?

August 2, 2025
No Comments

Traits are a way to reuse method code in multiple classes without inheritance. They are defined using the trait keyword and included in a class using use. Traits help overcome PHP’s single inheritance limitation. You can use multiple traits in a class, and resolve method conflicts using insteadof and as. Traits promote clean, reusable OOP design.

1. Why Use Traits?

PHP doesn’t support multiple inheritance (a class can’t extend more than one class), but Traits solve this by allowing you to reuse method logic across multiple classes.

2. Basic Trait Example


trait Logger {
    public function log($msg) {
        echo "Log: " . $msg;
    }
}

class User {
    use Logger;  // Include trait

    public function create() {
        $this->log("User created");
    }
}

$user = new User();
$user->create();  // Output: Log: User created

File: trait_basic.php

3. Using Multiple Traits


trait A {
    public function methodA() {
        echo "A";
    }
}

trait B {
    public function methodB() {
        echo "B";
    }
}

class MyClass {
    use A, B;
}

$obj = new MyClass();
$obj->methodA();  // Output: A
$obj->methodB();  // Output: B

File: multiple_traits.php

4. Trait Conflict Resolution


trait A {
    public function test() {
        echo "From A";
    }
}

trait B {
    public function test() {
        echo "From B";
    }
}

class Demo {
    use A, B {
        B::test insteadof A;   // Use B's version
        A::test as testA;      // Alias A's version
    }
}

$obj = new Demo();
$obj->test();   // Output: From B
$obj->testA();  // Output: From A

File: trait_conflict.php