PHP array()函数

定义和用法

array() 函数用于创建PHP数组。此函数可用于创建索引数组或关联数组。PHP数组可以是单维的或多维的。

语法

创建PHP索引数组的语法：

$a = array(value1, value2, value3, ...)

创建PHP关联数组的语法：

$a = array(key1 => value1, key2 => value2...)

参数

返回值

这个函数返回一个参数数组。

PHP版本

这个函数是作为核心PHP 4.0.0的一部分首次引入的。

示例

以下示例创建一个空的PHP数组：

<?php
   abc = array();
   print_r(abc);
?>

这将产生以下结果：

Array ()

示例

以下示例创建一个带有几个元素的PHP索引数组：

<?php
   abc = array("A", "B", "C");
   print_r(abc);
?>

这将产生以下结果−

Array
(
    [0] => A
    [1] => B
    [2] => C
)

示例

下面的示例创建了一个带有数字作为键的PHP关联数组:

<?php
   abc = array(1 => "One", 2 => "Two", 3 => "Three");
   print_r(abc);
?>

这将产生以下结果：

Array
(
    [1] => One
    [2] => Two
    [3] => Three
)

示例

下面的示例创建一个带有字符串键的PHP关联数组：

<?php
   abc = array("one" => "One", "two" => "Two", "three" => "Three");
   print_r(abc);
?>

这将产生以下结果 −

Array
(
    [one] => One
    [two] => Two
    [three] => Three
)

示例

以下示例展示了如何在现有PHP数组中添加更多的值：

<?php
   abc = array(1 => "One", 2 => "Two", 3 => "Three");
   print_r(abc);

   /* Add two more value in above array */
   abc[4] = "Four";abc[5] = "Five";
   print_r($abc);
?>

这将产生以下结果−

Array
(
    [1] => One
    [2] => Two
    [3] => Three
)

Array
(
    [1] => One
    [2] => Two
    [3] => Three
    [4] => Four
    [5] => Five
)

示例

以下示例演示了如何创建二维数组，如何为关联数组指定键，以及如何在普通数组中跳过并继续数字索引。

<?php
   fruits = array (
      "fruits"  => array("a" => "orange", "b" => "banana", "c" => "apple"),
      "numbers" => array(1, 2, 3, 4, 5, 6),
      "holes" => array("first", 5 => "second", "third")
   );
   print_r(fruits);
?>

这将产生以下结果 –

Array
(
    [fruits] => Array
        (
            [a] => orange
            [b] => banana
            [c] => apple
        )

    [numbers] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
            [3] => 4
            [4] => 5
            [5] => 6
        )

    [holes] => Array
        (
            [0] => first
            [5] => second
            [6] => third
        )

)

示例

要删除单个数组元素或完整数组，可以使用 unset() 函数：

<?php
   abc = array(1 => "One", 2 => "Two", 3 => "Three");
   print_r(abc);

   /* Now let's delete element with index 2*/
   unset( abc[2] );
   print_r(abc);

   /* Now let's delete complete array */
   unset(abc);
   print_r(abc);
?>

这将产生以下结果 –

Array
(
    [1] => One
    [2] => Two
    [3] => Three
)

Array
(
    [1] => One
    [3] => Three
)

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