Question

我有这个数组，有4个值= 3，我如何只删除其中两个？

Array ( 
    [0] => 1 
    [1] => 2 
    [2] => 1 
    [3] => 2
    [4] => 3
    [5] => 3
    [6] => 3 
    [7] => 2
    [8] => 2
    [9] => 2
    [10] => 1
    [11] => 2
    [12] => 3
    [13] => 2 
)

我已经尝试过unset()。有什么办法可以做到这一点？

所以数组看起来像这样

Array ( 
    [0] => 1
    [1] => 2
    [2] => 1
    [3] => 2
    [4] => 3 
    [5] => 3
    [6] => 2
    [7] => 2 
    [8] => 2 
    [9] => 1
    [10] => 2
    [11] => 2 
)

Answer 1

只需使用unset对array_search进行两次呼叫：

$array = array(1,2,3,3,3,4,5,6);
print_r($array);
unset($array[array_search(3, $array)]);
unset($array[array_search(3, $array)]);
print_r($array);

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 3
    [4] => 3
    [5] => 4
    [6] => 5
    [7] => 6
)

Array
(
    [0] => 1
    [1] => 2
    [4] => 3
    [5] => 4
    [6] => 5
    [7] => 6
)

但这假设您对array_search的行为感到满意，该行为将返回与值3匹配的 first 索引。如果您有其他删除顺序，然后声明它，然后可能需要更改代码。

Answer 2

您可以使用循环，并在遇到3时跳过前两次。然后，对于下一个匹配项，可以使用unset。然后，您可以使用array_values重置密钥：

$items = [
    1,2,1,2,3,3,3,2,2,2,1,2,3,2
];

$found  = 0;
foreach ($items as $key => $item) {
    if ($item === 3) {
        if ($found < 2) {
            $found++;
            continue;
        }
        unset($items[$key]);
    }
}
print_r(array_values($items));

结果

Array
(
    [0] => 1
    [1] => 2
    [2] => 1
    [3] => 2
    [4] => 3
    [5] => 3
    [6] => 2
    [7] => 2
    [8] => 2
    [9] => 1
    [10] => 2
    [11] => 2
)

Php demo

php数组基于值删除n个项目

2 个答案: