__toString for string representation in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the __toString method in PHP?

The <code>__toString</code> method allows a class to define how its objects are converted to a string, for example when echoing the object.

beginner

How do you declare the __toString method in a PHP class?

You declare it as a public method named <code>__toString</code> that returns a string. Example:<br><pre>public function __toString(): string { return 'text'; }</pre>

beginner

What happens if you try to echo an object without a __toString method?

PHP will throw a fatal error because it does not know how to convert the object to a string.

intermediate

Can the __toString method accept parameters?

No, the __toString method cannot accept any parameters. It must be declared without arguments.

beginner

Give a simple example of a PHP class with a <code>__toString</code> method.

Example:<br><pre>class Person {
  private string $name;
  public function __construct(string $name) {
    $this->name = $name;
  }
  public function __toString(): string {
    return "Person: " . $this->name;
  }
}
$person = new Person('Anna');
echo $person; // Outputs: Person: Anna</pre>

What does the __toString method in PHP return?

A A string representation of the object

B An integer value

C A boolean value

D Nothing, it is void

The __toString method must return a string that represents the object.

What happens if you echo an object without a __toString method?

A PHP prints nothing

B PHP prints 'Object'

C PHP prints 'Array'

D PHP throws a fatal error

PHP cannot convert the object to a string without __toString and throws a fatal error.

Which of these is the correct signature for __toString?

A public function __toString(): string

B public function __toString(string $param): string

C private function __toString()

D public function __toString(): void

__toString must be public, take no parameters, and return a string.

Can __toString be used to customize what is shown when an object is echoed?

A Only if the object implements an interface

B Yes

C No

D Only in PHP 8+

The main use of __toString is to customize the string shown when echoing an object.

Which keyword is used to define the __toString method?

A def

B method

C function

D proc

In PHP, methods are defined using the function keyword.

Explain what the __toString method does in PHP and why it is useful.

Think about how objects behave when printed.

Write a simple PHP class with a __toString method that returns a custom message.

Remember the method signature and return type.