Description
array
array_keys ( array input [,
mixed search_value])
array_keys() returns the keys,
numeric and string, from the
input array.
If the optional
search_value is specified, then only the keys for
that value are returned. Otherwise, all the keys from the input are returned.
範例 1. array_keys()
example
$array = array (0 = 100, "color" = "red");
print_r(array_keys ($array));
$array = array ("blue", "red", "green", "blue", "blue");
print_r(array_keys ($array, "blue"));
$array = array ("color" = array("blue", "red", "green"), "size" = array("small", "medium", "large"));
print_r(array_keys ($array));
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The printout of the program above will be:
Array
(
[0] = 0
[1] = color
)
Array
(
[0] = 0
[1] = 3
[2] = 4
)
Array
(
[0] = color
[1] = size
)
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注: This function was added to PHP 4, below is
an implementation for those still using PHP 3.
範例 2. Implementation of array_keys() for PHP 3
users
function array_keys ($arr, $term="") {
$t = array();
while (list($k,$v) = each($arr)) {
if ($term $v != $term) {
continue;
}
$t[] = $k;
}
return $t;
}
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See also array_values().