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PHP数组array类常见操作示例

程序员文章站 2022-05-14 21:25:13
本文实例讲述了php数组array类常见操作。分享给大家供大家参考,具体如下:array_merge($arr1,$arr2....);//合并一个或多个数组例:1、

本文实例讲述了php数组array类常见操作。分享给大家供大家参考,具体如下:

array_merge($arr1,$arr2....);//合并一个或多个数组

例:

1、

<?php
$beginning = 'foo';
$end = array(1 => 'bar');
$result = array_merge((array)$beginning, (array)$end);
print_r($result);
?> 

以上例程会输出:

    array
    (
        [0] => foo
        [1] => bar
    )

2、

<?php
$array1 = array("color" => "red", 2, 4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4);
$result = array_merge($array1, $array2);
print_r($result);
?> 

以上例程会输出:

array
(
    [color] => green
    [0] => 2
    [1] => 4
    [2] => a
    [3] => b
    [shape] => trapezoid
    [4] => 4
)

3、

<?php
$array1 = array();
$array2 = array(1 => "data");
$result = array_merge($array1, $array2);
?> 

别忘了数字键名将会被重新编号!

array
(
    [0] => data
)

4、

<?php
$array1 = array(0 => 'zero_a', 2 => 'two_a', 3 => 'three_a');
$array2 = array(1 => 'one_b', 3 => 'three_b', 4 => 'four_b');
$result = $array1 + $array2;
var_dump($result);
?> 

运行结果:

array(5) {
  [0]=>
  string(6) "zero_a"
  [2]=>
  string(5) "two_a"
  [3]=>
  string(7) "three_a"
  [1]=>
  string(5) "one_b"
  [4]=>
  string(6) "four_b"
}

array_diff($arr1,$arr2);//计算数组的差集(对比返回在 array1 中但是不在 array2 及任何其它参数数组中的值。)

例:

<?php
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);
print_r($result);
?> 

在 $array1 中多次出现的值一样处理,输出结果为:

array
(
    [1] => blue
)

array_diff_assoc($arr1,$arr2...);//带索引检查计算数组的差集

array_diff_assoc() 返回一个数组,该数组包括了所有在 array1 中但是不在任何其它参数数组中的值

<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "green", "yellow", "red");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?> 

以上例程会输出:

array
(
    [b] => brown
    [c] => blue
    [0] => red
)

array_keys($array);//返回数组中部分的或所有的键名(返回 input 数组中的数字或者字符串的键名。)

<?php
$array = array(0 => 100, "color" => "red");
print_r(array_keys($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));
?>

以上例程会输出:

array
(
    [0] => 0
    [1] => color
)
array
(
    [0] => 0
    [1] => 3
    [2] => 4
)
array
(
    [0] => color
    [1] => size
)

array_slice($array, $offset, $length);//从数组中取出一段

参数:array::输入的数组, offset:序列偏移量, length:单元长度

$input = array("a", "b", "c", "d", "e");
$output = array_slice($input, 2);   // returns "c", "d", and "e"
$output = array_slice($input, -2, 1); // returns "d"
$output = array_slice($input, 0, 3);  // returns "a", "b", and "c"