The Generator class

(PHP 5 >= 5.5.0)

Introduction

Generator objects are returned from generators.

Caution

Generator objects cannot be instantiated via new.

Class synopsis

Generator implements Iterator {

/* Methods */

public mixed current ( void )

public mixed key ( void )

public void next ( void )

public void rewind ( void )

public mixed send ( mixed $value )

public mixed throw ( Exception $exception )

public bool valid ( void )

public void __wakeup ( void )

}

Generator::current — Get the yielded value
Generator::key — Get the yielded key
Generator::next — Resume execution of the generator
Generator::rewind — Rewind the iterator
Generator::send — Send a value to the generator
Generator::throw — Throw an exception into the generator
Generator::valid — Check if the iterator has been closed
Generator::__wakeup — Serialize callback

Коментарии

Feb 05

Автор: Pistachio


Unlike return, yield can be used anywhere within a function so logic can flow more naturally. Take for example the following Fibonacci generator:



<?php

function fib($n)

{

    $cur = 1;

    $prev = 0;

    for ($i = 0; $i < $n; $i++) {

        yield $cur;



        $temp = $cur;

        $cur = $prev + $cur;

        $prev = $temp;

    }

}



$fibs = fib(9);

foreach ($fibs as $fib) {

    echo " " . $fib;

}



// prints: 1 1 2 3 5 8 13 21 34