dqwyghl0649 2017-10-05 04:57 采纳率: 0%
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从当前位置获取数组中的上一个和下一个键/值(PHP)

I have an array similar to the following:

const BookIndex = array
(
    '1' => 'Chapter 1',
    '1.1' => 'Chapter 1.1',
    '1.1.1' => 'Chapter 1.1.1',
    '2' => 'Chapter 2',
    '2.1' => 'Chapter 2.1',
    '2.1.1' => 'Chapter 2.1.1',
);

Let's say that I have determined somehow that the current key (position) I care about is the '2' key. How do I find the previous and next keys?

$CurrentKey = '2';
$CurrentValue = BookIndex[$CurrentKey];

$PreviousKey = null; // I need to figure out the previous key from the current key.
$PreviousValue = BookIndex[$PreviousKey];

$NextKey = null; // I need to figure out the next key from the current key.
$NextValue = BookIndex[$NextKey];
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  • doutui4649 2017-10-05 05:00
    关注

    You can use array functions for that

    $NextKey = next($BookIndex); // next key of array
    
    $PreviousKey = prev($BookIndex); // previous key of array
    
    $CurrentKey = current($BookIndex); // current key of array
    

    pointing to specific position

    $CurrentKey = '2';
    
    while (key($BookIndex) !== $CurrentKey) next($BookIndex);
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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