有没有一种简单的方法可以使用PHP从数组中删除元素,从而foreach($array)不再包含该元素?

我以为将其设置为null就可以了,但显然它不起作用。


当前回答

  // Our initial array
  $arr = array("blue", "green", "red", "yellow", "green", "orange", "yellow", "indigo", "red");
  print_r($arr);

  // Remove the elements who's values are yellow or red
  $arr = array_diff($arr, array("yellow", "red"));
  print_r($arr);

这是上面代码的输出:

Array
(
    [0] => blue
    [1] => green
    [2] => red
    [3] => yellow
    [4] => green
    [5] => orange
    [6] => yellow
    [7] => indigo
    [8] => red
)

Array
(
    [0] => blue
    [1] => green
    [4] => green
    [5] => orange
    [7] => indigo
)

现在,array_values()将很好地重新索引数字数组,但它将从数组中删除所有键字符串,并用数字替换它们。如果需要保留键名称(字符串),或者如果所有键都是数字,则重新索引数组,请使用array_merge():

$arr = array_merge(array_diff($arr, array("yellow", "red")));
print_r($arr);

输出

Array
(
    [0] => blue
    [1] => green
    [2] => green
    [3] => orange
    [4] => indigo
)

其他回答

需要注意的是,unset()将保持索引不变,这是使用字符串索引(数组作为哈希表)时所期望的,但在处理整数索引数组时可能会非常令人惊讶:

$array = array(0, 1, 2, 3);
unset($array[2]);
var_dump($array);
/* array(3) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [3]=>
  int(3)
} */

$array = array(0, 1, 2, 3);
array_splice($array, 2, 1);
var_dump($array);
/* array(3) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(3)
} */

因此,如果您想规范化整数键,可以使用array_splice()。另一个选项是在unset()之后使用array_values():

$array = array(0, 1, 2, 3);

unset($array[2]);
$array = array_values($array);
var_dump($array);
/* array(3) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(3)
} */

如果您必须删除数组中的多个值,并且该数组中的条目是对象或结构化数据,那么array_filter()是最佳选择。那些从回调函数返回true的条目将被保留。

$array = [
    ['x'=>1,'y'=>2,'z'=>3], 
    ['x'=>2,'y'=>4,'z'=>6], 
    ['x'=>3,'y'=>6,'z'=>9]
];

$results = array_filter($array, function($value) {
    return $value['x'] > 2; 
}); //=> [['x'=>3,'y'=>6,z=>'9']]

销毁阵列的单个元素

取消设置()

$array1 = array('A', 'B', 'C', 'D', 'E');
unset($array1[2]); // Delete known index(2) value from array
var_dump($array1);

输出将为:

array(4) {
  [0]=>
  string(1) "A"
  [1]=>
  string(1) "B"
  [3]=>
  string(1) "D"
  [4]=>
  string(1) "E"
}

如果需要重新索引阵列:

$array1 = array_values($array1);
var_dump($array1);

那么输出将是:

array(4) {
  [0]=>
  string(1) "A"
  [1]=>
  string(1) "B"
  [2]=>
  string(1) "D"
  [3]=>
  string(1) "E"
}

从数组末尾弹出元素-返回移除元素的值

混合数组pop(array&$array)

$stack = array("orange", "banana", "apple", "raspberry");
$last_fruit = array_pop($stack);
print_r($stack);
print_r('Last Fruit:'.$last_fruit); // Last element of the array

输出将为

Array
(
    [0] => orange
    [1] => banana
    [2] => apple
)
Last Fruit: raspberry

从数组中移除第一个元素(红色),返回移除元素的值

混合array_shift(array&$array)

$color = array("a" => "red", "b" => "green" , "c" => "blue");
$first_color = array_shift($color);
print_r ($color);
print_r ('First Color: '.$first_color);

输出将为:

Array
(
    [b] => green
    [c] => blue
)
First Color: red

使用以下代码:

$arr = array('orange', 'banana', 'apple', 'raspberry');
$result = array_pop($arr);
print_r($result);
  // Our initial array
  $arr = array("blue", "green", "red", "yellow", "green", "orange", "yellow", "indigo", "red");
  print_r($arr);

  // Remove the elements who's values are yellow or red
  $arr = array_diff($arr, array("yellow", "red"));
  print_r($arr);

这是上面代码的输出:

Array
(
    [0] => blue
    [1] => green
    [2] => red
    [3] => yellow
    [4] => green
    [5] => orange
    [6] => yellow
    [7] => indigo
    [8] => red
)

Array
(
    [0] => blue
    [1] => green
    [4] => green
    [5] => orange
    [7] => indigo
)

现在,array_values()将很好地重新索引数字数组,但它将从数组中删除所有键字符串,并用数字替换它们。如果需要保留键名称(字符串),或者如果所有键都是数字,则重新索引数组,请使用array_merge():

$arr = array_merge(array_diff($arr, array("yellow", "red")));
print_r($arr);

输出

Array
(
    [0] => blue
    [1] => green
    [2] => green
    [3] => orange
    [4] => indigo
)