php include和require的区别深入解析

复制代码 代码如下:

<?php
$color = 'green';
$fruit = 'apple';
?>

复制代码 代码如下:

<?php
echo "A $color $fruit"; // A
include 'vars.php';
echo "A $color $fruit"; // A green apple
?>

复制代码 代码如下:

<?php
function foo()
{
global $color;
include 'vars.php';
echo "A $color $fruit";
}
/* vars.php is in the scope of foo() so *
* $fruit is NOT available outside of this *
* scope. $color is because we declared it *
* as global. */
foo(); // A green apple
echo "A $color $fruit"; // A green
?>

复制代码 代码如下:

<?php
/* This example assumes that is configured to parse .php *
* files and not .txt files. Also, 'Works' here means that the variables *
* $foo and $bar are available within the included file. */
// Won't work; file.txt wasn't handled by as PHP
include 'http://www.example.com/file.txt?foo=1&bar=2';

// Won't work; looks for a file named 'file.php?foo=1&bar=2' on the
// local filesystem.
include 'file.php?foo=1&bar=2';

// Works.
include 'http://www.example.com/file.php?foo=1&bar=2';

$foo = 1;
$bar = 2;
include 'file.txt'; // Works.
include 'file.php'; // Works.
?>

复制代码 代码如下:

<?php
// This is WRONG and will not work as desired.
if ($condition)
include $file;
else
include $other;
// This is CORRECT.
if ($condition) {
include $file;
} else {
include $other;
}
?>

复制代码 代码如下:

<?php
$var = 'PHP';
return $var;
?>

复制代码 代码如下:

<?php
$var = 'PHP';
?>

复制代码 代码如下:

<?php
$foo = include 'return.php';
echo $foo; // prints 'PHP'
$bar = include 'noreturn.php';
echo $bar; // prints 1
?>