PHP:将数组求和为多维数组
PHP:将数组求和为多维数组
提问于 2018-07-06 04:02:55
我有一个存储章节、问题和答案的数组。正如您在示例中所看到的，这并不是很方便。
我想要的是一个多维数组。
在PHP中做这件事的最佳实践是什么？
我所拥有的：
array(
array(
'chapter' => 'Chapter 1',
'question' => 'Question 1',
'answer' => 'Answer 1'
),
array(
'chapter' => 'Chapter 1',
'question' => 'Question 1',
'answer' => 'Answer 2'
),
array(
'chapter' => 'Chapter 1',
'question' => 'Question 2',
'answer' => 'Answer 1'
),
array(
'chapter' => 'Chapter 2',
'question' => 'Question 1',
'answer' => 'Answer 1'
),
array(
'chapter' => 'Chapter 2',
'question' => 'Question 1',
'answer' => 'Answer 2'
)
);我想要的是：
array(
array(
'chapter' => 'Chapter 1',
'questions' => array(
array(
'text' => 'Question 1',
'answers' => array(
'Answer 1',
'Answer 2'
)
),
array(
'text' => 'Question 2',
'answers' => array(
'Answer 1'
)
)
)
),
array(
'chapter' => 'Chapter 2',
'questions' => array(
array(
'text' => 'Question 1',
'answers' => array(
'Answer 1',
'Answer 2'
)
)
)
)
); 回答 1
Stack Overflow用户
回答已采纳
发布于 2018-07-06 04:33:31
好吧，我会使用array_reduce、array_map和array_values的一些组合：
<?php
$input = array(
array(
'chapter' => 'Chapter 1',
'question' => 'Question 1',
'answer' => 'Answer 1'
),
array(
'chapter' => 'Chapter 1',
'question' => 'Question 1',
'answer' => 'Answer 2'
),
array(
'chapter' => 'Chapter 1',
'question' => 'Question 2',
'answer' => 'Answer 1'
),
array(
'chapter' => 'Chapter 2',
'question' => 'Question 1',
'answer' => 'Answer 1'
),
array(
'chapter' => 'Chapter 2',
'question' => 'Question 1',
'answer' => 'Answer 2'
)
);
$result = array_reduce(
$input,
function($output, $inputElem) {
$output[$inputElem['chapter']]['chapter'] = $inputElem['chapter'];
$output[$inputElem['chapter']]['questions'][$inputElem['question']]['text'] = $inputElem['question'];
$output[$inputElem['chapter']]['questions'][$inputElem['question']]['answers'][] = $inputElem['answer'];
return $output;
},
[]
);
/* So now $result looks like this:
array(
"Chapter 1"=> array(
"chapter"=> "Chapter 1"
"questions"=> array(
"Question 1"=> array(
"text"=> "Question 1"
"answers"=> array(
"Answer 1",
"Answer 2"
)
)
"Question 2"=> array(
"text"=> "Question 2"
"answers"=> array(
"Answer 1"
)
)
)
)
"Chapter 2"=> array(
"chapter"=> "Chapter 2"
"questions"=> array(
"Question 1"=> array(
"text"=> "Question 1"
"answers"=> array(
"Answer 1",
"Answer 2"
)
)
)
)
)
*/
//we need to remove redundant keys now
$result = array_values( //removes main "chapter" keys
array_map(
function($chapter) {
$chapter['questions'] = array_values($chapter['questions']); //removes "question" keys
return $chapter;
},
$result
)
);
var_dump($result);页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/51199046
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