Question

我在php中遇到一个小问题，我知道解决方案很简单，但是我似乎无法解决它。

基本上，我有一个数组，需要用到它的一小部分。

<?php

$main = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);
$start = 5;

$sliced = array_slice($main, $start);

$offset=3;


$startx = $start;

foreach($sliced as $s)
{

    $start_pt = $startx-$offset;
    $end_pt = ($startx) - count($main);

    $sli = array_slice($main,$start_pt,$end_pt+1);

    print_r($sli);
    echo "<br>##############################<br>";

    $startx++;
}

除了最后一个返回空白的数组之外，上面的方法还行得通，因为长度现在为-1或-0。将其作为长度而不是偏移量。

有什么更简单/更好的方法来做到这一点？

结果：

Array ( [0] => 3 [1] => 4 [2] => 5 [3] => 6 )
##############################
Array ( [0] => 4 [1] => 5 [2] => 6 [3] => 7 )
##############################
Array ( [0] => 5 [1] => 6 [2] => 7 [3] => 8 )
##############################
Array ( [0] => 6 [1] => 7 [2] => 8 [3] => 9 )
##############################
Array ( [0] => 7 [1] => 8 [2] => 9 [3] => 10 )
##############################
Array ( [0] => 8 [1] => 9 [2] => 10 [3] => 11 )
##############################
Array ( [0] => 9 [1] => 10 [2] => 11 [3] => 12 )
##############################
Array ( [0] => 10 [1] => 11 [2] => 12 [3] => 13 )
##############################
Array ( [0] => 11 [1] => 12 [2] => 13 [3] => 14 )
##############################
Array ( )
##############################

Answer 1

我认为您的目的是从数组中创建相同长度的重叠范围，因此您可以尝试以下操作：

<?php
$main = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);

function overlapped_chunks($array,$start,$length,$overlap=False){
    if(!is_array($array)||!is_int($start)||!is_int($length))
        return;
    $go=false;
    $range=[];
    for($i=0;false!==key($array)&&NULL!==key($array);$i++){
        $temp=[];
        list(,$value)=each($array);
        if($i===$start){
            $go=true;
        }
        if($go){
            $range[]=$value;
        }
        if(count($range)===$length){
            $temp=$range;
            $range=array_slice($range,$length-(is_int($overlap)&&$overlap<$length&&$overlap>=0?$overlap:$length-($length-1)));
            yield $temp;
        }   
    }

    if($value!==end($temp)) yield $range;
}



foreach(overlapped_chunks($main,2,4,3) as $k=>$v){
     print_r($v);
    echo "<br>##############################<br>";


}

?>

这将打印

    Array ( [0] => 3 [1] => 4 [2] => 5 [3] => 6 ) 
##############################
Array ( [0] => 4 [1] => 5 [2] => 6 [3] => 7 ) 
##############################
Array ( [0] => 5 [1] => 6 [2] => 7 [3] => 8 ) 
##############################
Array ( [0] => 6 [1] => 7 [2] => 8 [3] => 9 ) 
##############################
Array ( [0] => 7 [1] => 8 [2] => 9 [3] => 10 ) 
##############################
Array ( [0] => 8 [1] => 9 [2] => 10 [3] => 11 ) 
##############################
Array ( [0] => 9 [1] => 10 [2] => 11 [3] => 12 ) 
##############################
Array ( [0] => 10 [1] => 11 [2] => 12 [3] => 13 ) 
##############################
Array ( [0] => 11 [1] => 12 [2] => 13 [3] => 14 ) 
##############################
Array ( [0] => 12 [1] => 13 [2] => 14 [3] => 15 ) 
##############################

它既可以用于有序数组，也可以用于关联数组

Answer 2

您想使用array_slice()和array_chunk()

轻松地完成操作

首先，您需要对数组进行切片以获取偏移量，然后将其拆分为大块

<?php

$arr = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16);
$offset = 3;
$start = 5;

$splitedArr = array_slice($arr, $start);

for ($i = 0, $size = floor(count($splitedArr) / $offset); $i < $size; $i += $offset) {
  $sli = array_chunk($splitedArr, $offset);
  print_r($sli); 
}

因此，它的作用是遍历为第一个偏移量切片的数组，然后计算应迭代数组大小/块大小的次数，并在每次迭代时增加块的大小。它实际上在循环内部制作了块并将其打印出来。

输出：

Array
(
    [0] => Array
        (
            [0] => 6
            [1] => 7
            [2] => 8
        )

    [1] => Array
        (
            [0] => 9
            [1] => 10
            [2] => 11
        )

    [2] => Array
        (
            [0] => 12
            [1] => 13
            [2] => 14
        )

    [3] => Array
        (
            [0] => 15
            [1] => 17
        )

)

PHP：数组切片问题

2 个答案: