打印一个平面数组，并在循环中删除一个值

Question

如何在 foreach 循环中包含相同的数组并删除另一个数组中的相同值。我的PHP技术不强，想向这里的专家寻求帮助。请看下面的场景。

$array = array("group1","group2","group3","group4");
//Result should be
group1 = group2,group3,group4
group2 = group1,group3,group4
group3 = group1,group2,group4
group4 = group1,group2,group3

我只在：

 $array = array('group1','group2','group3','group4');


foreach($array as $value){
  echo '<br>'.$prodfilters.'= <br>';
  foreach($arrayFilter as $xx){
    echo $xx.'<br>';
  }
}
//Result
group1 = group1,group2,group3,group4
group2 = group1,group2,group3,group4
group3 = group1,group2,group3,group4
group4 = group1,group2,group3,group4
//basically repeating itself each value from the outer foreach loop instead of removing the same value from the inner foreach loop.

Answer 1

这是使用

array_walk

和

array_diff

函数的简短解决方案：

$array = ["group1","group2","group3","group4"];
$result = [];

array_walk($array, function($v) use(&$result, $array){
    $result[$v] = array_diff($array, [$v]);   // it can be imploded into a string if needed
});

print_r($result);

输出：

Array
(
    [group1] => Array
        (
            [1] => group2
            [2] => group3
            [3] => group4
        )

    [group2] => Array
        (
            [0] => group1
            [2] => group3
            [3] => group4
        )

    [group3] => Array
        (
            [0] => group1
            [1] => group2
            [3] => group4
        )

    [group4] => Array
        (
            [0] => group1
            [1] => group2
            [2] => group3
        )
)

现在您可以通过将其“名称”指定为数组键来访问每个项目，例如

$result['group3']

Answer 2

<?php
$array = ["group1","group2","group3","group4"];
$new = [];
foreach ($array as $key1) {
    $new[$key1] = [];
    foreach ($array as $key2) {
        if ($key1 !== $key2) {
            $new[$key1][] = $key2;
        }
    }
}
print_r($new);

Answer 3

我不完全确定你想要实现什么。 这里有一个迭代建议：

foreach($array as $value){
     $result.=$value.' = ';
     foreach($array as $value2){
         if($value2 != $value){
              $result.=$value2.',';
         }
     }
     $result.=rtrim($result,',').'\n'; //replace \n with <br/> for html linefeed
}
echo $result;

Answer 4

这是一个有趣的解决方案，因为它利用了：

• 变量变量
• 匿名函数闭包

• use

  父变量作用域

还有一些有用的数组函数：

• array_filter

• array_values

  重置索引

这将提供单独的数组，每个数组都以主数组中各自的值命名：

<?php
$array = array("group1","group2","group3","group4");

foreach ($array as $element)
  $$element = array_values(array_filter($array,function($item) use ($element){return $item !== $element; }));

现在您可以通过索引名称使用各个数组：

print_r($group1);

显示这个：

Array
(
    [0] => group2
    [1] => group3
    [2] => group4
)

并且您可以使用

get_defined_vars

查看环境中的所有变量

print_r(get_defined_vars());

在源代码中显示这一点：

[group1] => Array
    (
        [0] => group2
        [1] => group3
        [2] => group4
    )

[group2] => Array
    (
        [0] => group1
        [1] => group3
        [2] => group4
    )

[group3] => Array
    (
        [0] => group1
        [1] => group2
        [2] => group4
    )

[group4] => Array
    (
        [0] => group1
        [1] => group2
        [2] => group3
    )