array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'zh', ), 'this' => array ( 0 => 'ds-map.haskey.php', 1 => 'Ds\\Map::hasKey', 2 => 'Determines whether the map contains a given key', ), 'up' => array ( 0 => 'class.ds-map.php', 1 => 'Ds\\Map', ), 'prev' => array ( 0 => 'ds-map.get.php', 1 => 'Ds\\Map::get', ), 'next' => array ( 0 => 'ds-map.hasvalue.php', 1 => 'Ds\\Map::hasValue', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'en', 'path' => 'reference/ds/ds/map/haskey.xml', ), 'history' => array ( ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); contributors($setup); ?>

Ds\Map::hasKey

(PECL ds >= 1.0.0)

Ds\Map::hasKey — Determines whether the map contains a given key

说明

public Ds\Map::hasKey(mixed $key): bool

Determines whether the map contains a given key.

参数

key: The key to look for.

返回值

Returns true if the key could found, false otherwise.

示例

示例 #1 Ds\Map::hasKey() example

<?php
$map = new \Ds\Map(["a" => 1, "b" => 2, "c" => 3]);

var_dump($map->hasKey("a")); // true
var_dump($map->hasKey("e")); // false
?>

以上示例的输出类似于：

bool(true)
bool(false)