Delicious Bookmark this on Delicious Share on Facebook SlashdotSlashdot It! Digg! Digg



PHP : Function Reference : Variable Handling Functions : is_resource

is_resource

Finds whether a variable is a resource (PHP 4, PHP 5)
bool is_resource ( mixed var )

Example 2593. is_resource() example

<?php

$db_link
= @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
if (!
is_resource($db_link)) {
   die(
'Can\'t connect : ' . mysql_error());
}

?>

Code Examples / Notes » is_resource

tacomage

Note that the use of is_resource isn't necessary in the example.  mysql_connect (along with any other function that would return a resouce, I imagine) returns false on failure, so the same results could be obtained with:
<?php
$db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
if (!$db_link) {
  die('Can\'t connect : ' . mysql_error());
}
?>
Or even:
<?php
 $db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass')
 or die('Can\'t connect : ' . mysql_error());
}
?>
You'd be more likely to use is_resource AFTER the initial conection, to make sure the variable you intend to use as a resource is, in fact, a connection resource.  You might also use is_resource as a sanity-check prior to serializing an object, since resource variables can't be serialized.


Change Language


Follow Navioo On Twitter
debug_zval_dump
doubleval
empty
floatval
get_defined_vars
get_resource_type
gettype
import_request_variables
intval
is_array
is_binary
is_bool
is_buffer
is_callable
is_double
is_float
is_int
is_integer
is_long
is_null
is_numeric
is_object
is_real
is_resource
is_scalar
is_string
is_unicode
isset
print_r
serialize
settype
strval
unserialize
unset
var_dump
var_export
eXTReMe Tracker