PHP - var_dump() Function
Definition and Usage
The function var_dump() displays structured information (type and value) about one or more expressions/variables.
Arrays and objects are explored recursively with values indented to show structure.
All public, private and protected properties of objects will be returned in the output.
Syntax
void var_dump ( mixed $value , mixed $values )
Parameters
| Sr.No |
Parameter & Description |
| 1 |
value The expression to dump. |
| 2 |
values
Further expressions to dump. |
Return Values
This function returns no value. This function outputs results directly to the browser. The output can be captured using output-control functions and stored to a string.
Dependencies
PHP 4 and above
Example
Following example demonstrates use of var_dump() −
<?php
$a = "Welcome TutorialsPoint!";
var_dump($a);
echo "<br>";
$b = array(2,'hello',22.99, array('a','b',2));
var_dump($b);
?>
Output
This will produce following result −
string(23) "Welcome TutorialsPoint!"
array(4) {
[0]=> int(2)
[1]=> string(5) "hello"
[2]=> float(22.99)
[3]=> array(3) {
[0]=> string(1) "a"
[1]=> string(1) "b"
[2]=> int(2)
}
}
Example
Following example demonstrates storing the output of var_dump() to a variable, which can later be manipulated. To execute the example we have used two php functions (output-control functions) ob_start() and ob_get_clean(). ob_start() function turns output buffering on where as ob_get_clean() function gets current buffer contents and delete current output buffer.
<?php
ob_start();
var_dump("output var_dump data to a string");
$out = ob_get_clean();
echo $out;
echo("<br>");
echo substr($out,0,30);
?>
Output
This will produce following result −
string(32) "output var_dump data to a string"
string(32) "output var_dump da
php_variable_handling_functions.htm
