ksort

(PHP 3, PHP 4 , PHP 5)

ksort -- Sort an array by key

Description

bool ksort ( array &array [, int sort_flags])

Sorts an array by key, maintaining key to data correlations. This is useful mainly for associative arrays.

Returns TRUE on success or FALSE on failure.

Example 1. ksort() example

<?php
$fruits
= array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
ksort($fruits);
reset($fruits);
while (list(
$key, $val) = each($fruits)) {
    echo
"$key = $val\n";
}
?>

This example would display:

a = orange
b = banana
c = apple
d = lemon

You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().

See also asort(), arsort(), krsort(), uksort(), sort(), natsort(), and rsort().

Note: The second parameter was added in PHP 4.

color="#DD0000">'test' => 1, 'hello' => NULL);

var_dump(isset($a['test']));            // TRUE
var_dump(isset($a['foo']));             // FALSE
var_dump(isset($a['hello']));           // FALSE

// The key 'hello' equals NULL so is considered unset
// If you want to check for NULL key values then try:
var_dump(array_key_exists('hello', $a)); // TRUE

?>