有没有从第二个索引开始foreach的优雅方法，然后完成剩下的工作？

Question

如果我有以下几点：

$a = array(
    "one" => 1, 
    "two" => 2, 
    "three" => 3, 
    "seventeen" => 17 
); 

foreach ($a as $v) { 
    echo $v; 
} 

我怎样才能使输出：

2, 1, 3, 17 

Answer 1

引述PHP Manual on Language Operators：

+运算返回附加到左手 阵列右手阵列;对于这两个数组中存在的键，将使用左手阵列中的元素，而右边数组中的匹配元素将被忽略。

$a = array(
    "one" => 1, 
    "two" => 2, 
    "three" => 3, 
    "seventeen" => 17 
); 

$b = array_values($a); 
echo implode(', ', array($b[1], $b[0]) + $b), PHP_EOL; 

输出：

2, 1, 3, 17 

Answer 2

$values = array_values($a); 
echo "{$values[1]}, {$values[0]}, " 
foreach (array_slice($values, 2) as $v){ 
    echo "$v, " 
} 

如果你关心最后一个逗号......

$values = array_values($a); 
echo "{$values[1]}, {$values[0]}, " 
$lastIndex = count($values) - 1; 

foreach (array_slice($values, 2) as $k => $v){ 
    echo $v; 
    if ($k != $lastIndex){ 
     echo ", "; 
    } 
} 

Answer 3

你可以可能是这样做的：

<?php 

$my_array = array(...); 

$keys = array_keys($my_array); 
$second_key = $keys[1]; // if your array can be whatever size, probably want to check that first 

echo $my_array[$second_key]; 

foreach ($my_array as $key => $value) { 
    if ($key == $second_key) { 
    continue; 
    } 

    echo $value; 
} 

?>