PHP 7.1 is now released – Featuring nullable types, class constants, and more.

December 03, 2016 / Eric L. Barnes

Today, the PHP team has released 7.1.0 that includes new features such as Nullable types, Void return type, Class constant visibility modifiers, and more. Here is a quick overview of some of the new features.

Nullable Types

This adds a leading question mark indicate that a type can also be null.

function answer(): ?int  {
    return null; //ok
}

function answer(): ?int  {
    return 42; // ok
}

function answer(): ?int {
    return new stdclass(); // error
}

Void Return Type

This requires that a function not return any value:

function should_return_nothing(): void {
    return 1; // Fatal error: A void function must not return a value
}

function lacks_return(): void {
    // valid
}

function returns_nothing(): void {
    return; // valid
}

function returns_null(): void {
    return null; // Fatal error: A void function must not return a value
}

Class constant Visibility

You now have the ability to set the visibility on class constants.

class Token {
    // Constants default to public
    const PUBLIC_CONST = 0;

        // Constants then also can have a defined visibility
        private const PRIVATE_CONST = 0;
        protected const PROTECTED_CONST = 0;
        public const PUBLIC_CONST_TWO = 0;

        //Constants can only have one visibility declaration list
        private const FOO = 1, BAR = 2;
}

For a full list of new features take a look at the release announcement and the changelog. Also, Amo Chohan has a great article highlighting all the changes in PHP 7.1.

Filed in: News / PHP