What is the difference between the three functions var_dump, var_export and print_r in php?

This article is a detailed analysis and introduction to the differences between the three functions of var_dump, var_export and print_r in PHP. Friends in need can refer to it

The following example looks at the specific differences between these three functions. Var_dump and var_export are less commonly used, but they are very similar. So you can take a look:

The code is as follows:

<?php
$a = array(1,1,32,322,3433,array(32,232,23232));
$b = 1234;
$c = "alsdfl;asdf";
$d = &#39;a&#39;;
$e = fopen("slsl.txt", "r");
var_dump($a);
echo "<br>";
var_dump($b);
echo "<br>";
var_dump($c);
echo "<br>";
var_dump($d);
echo "<br>";
var_dump($e);
echo "<br>";
echo "<br>";
echo "<br>";
echo "<br>";
var_export($a);
echo "<br>";
var_export($b);
echo "<br>";
var_export($c);
echo "<br>";
var_export($d);
echo "<br>";
var_export($e);
echo "<br>";
echo "<br>";
echo "<br>";
echo "<br>";
print_r($a);
echo "<br>";
print_r($b);
echo "<br>";
print_r($c);
echo "<br>";
print_r($d);
echo "<br>";
print_r($e);
echo "<br>";

Output:

The code is as follows:

Warning: fopen(slsl.txt) [function.fopen]: failed to open stream: No such file or directory in E:\mywww\yangtest\base1.php on line 6
array(6) { [0]=> int(1) [1]=> int(1) [2]=> int(32) [3]=> int(322) [4]=> int(3433) [5]=> array(3) { [0]=> int(32) [1]=> int(232) [2]=> int(23232) } }
int(1234)
string(11) "alsdfl;asdf"
string(1) "a"
bool(false)
array ( 0 => 1, 1 => 1, 2 => 32, 3 => 322, 4 => 3433, 5 => array ( 0 => 32, 1 => 232, 2 => 23232, ), )
1234
'alsdfl;asdf'
'a'
false
Array ( [0] => 1 [1] => 1 [2] => 32 [3] => 322 [4] => 3433 [5] => Array ( [0] => 32 [1] => 232 [2] => 23232 ) )
1234
alsdfl;asdf
a

Now you can see the effect. Note that the last one is not that I didn’t paste it over, but that it didn’t display anything in the first place.

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