<code> $select = $this->datas->query("select data01 from ds_meters_320114102 ORDER BY id desc limit 24"); $result = $select->result(); $datas = array(); foreach($result as $row){ $datas[] = $row; } //var_dump($datas); echo json_encode($datas); </code>
以上是我查询数据库得出的json,这个json结果输出后是这样的格式:
<code>[{"data01":"20.90"},{"data01":"20.90"},{"data01":"21.00"},{"data01":"20.90"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"20.90"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"20.90"},{"data01":"20.90"},{"data01":"20.90"},{"data01":"20.90"},{"data01":"20.90"}] </code>
可是这个数据不是我想要的,我要把这个json变成这样的格式:
<code>[20.90,20.90,21.00,20.90,21.00,21.00....] </code>
请问如何实现呢?谢谢
回复内容:
<code> $select = $this->datas->query("select data01 from ds_meters_320114102 ORDER BY id desc limit 24"); $result = $select->result(); $datas = array(); foreach($result as $row){ $datas[] = $row; } //var_dump($datas); echo json_encode($datas); </code>
以上是我查询数据库得出的json,这个json结果输出后是这样的格式:
<code>[{"data01":"20.90"},{"data01":"20.90"},{"data01":"21.00"},{"data01":"20.90"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"20.90"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"21.00"},{"data01":"20.90"},{"data01":"20.90"},{"data01":"20.90"},{"data01":"20.90"},{"data01":"20.90"}] </code>
可是这个数据不是我想要的,我要把这个json变成这样的格式:
<code>[20.90,20.90,21.00,20.90,21.00,21.00....] </code>
请问如何实现呢?谢谢
如果是数字索引的数组,那么json_encode()的返回值就是[]括住的字符串;如果是字符串索引的数组,那么json_encode()的返回值就是{}括住的字符串。
所以,解决这个问题,可以尝试:echo json_encode(array_values($datas))
楼上已经可以完美解决楼主的问题了。
解决之余,应该多问问为什么。
- JSON 怎么会这样的?
- 为什么非要用 JSON 而不用 序列化(serialize)?
如果你是带着这种疑问,百度一下问题就可以解决。
JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。它使得人们很容易的进行阅读和编写。同时也方便了机器进行解析和生成。它是基于 JavaScript Programming Language , Standard ECMA-262 3rd Edition - December 1999 的一个子集。 JSON采用完全独立于程序语言的文本格式,但是也使用了类C语言的习惯(包括C, C++, C#, Java, JavaScript, Perl, Python等)。这些特性使JSON成为理想的数据交换语言。出处
JSON基于两种结构:
“名称/值”对的集合(A collection of name/value pairs)。不同的编程语言中,它被理解为对象(object),纪录(record),结构(struct),字典(dictionary),哈希表(hash table),有键列表(keyed list),或者关联数组 (associative array)。
值的有序列表(An ordered list of values)。在大部分语言中,它被实现为数组(array),矢量(vector),列表(list),序列(sequence)。出处
它一定是有自己的特点的,会了,那就永远都会了。学习一下吧 JSON 中国 | JSON 中文网
$datas[] = $row[data01];
需要你在上面的datas数组里把键data01去掉。
<code>PHP</code><code>foreach($result as $row) { $datas[] = $row['data01'] } </code>
这样就行了, 因为之前的数组里有字符串键data01所以只能生成Js对象 {"data01" : "20.90"}
才能表示键值关系。 你把$datas
换成自然索引的数组就可以了。
json_encode(array_column($datas,'data01'));
tips:php5.5才支持array_column,如果你的php版本低于这个就用上面的foreach循环吧

The article explains how to create, implement, and use interfaces in PHP, focusing on their benefits for code organization and maintainability.

The article discusses the differences between crypt() and password_hash() in PHP for password hashing, focusing on their implementation, security, and suitability for modern web applications.

Article discusses preventing Cross-Site Scripting (XSS) in PHP through input validation, output encoding, and using tools like OWASP ESAPI and HTML Purifier.

Autoloading in PHP automatically loads class files when needed, improving performance by reducing memory use and enhancing code organization. Best practices include using PSR-4 and organizing code effectively.

PHP streams unify handling of resources like files, network sockets, and compression formats via a consistent API, abstracting complexity and enhancing code flexibility and efficiency.

The article discusses managing file upload sizes in PHP, focusing on the default limit of 2MB and how to increase it by modifying php.ini settings.

The article discusses nullable types in PHP, introduced in PHP 7.1, allowing variables or parameters to be either a specified type or null. It highlights benefits like improved readability, type safety, and explicit intent, and explains how to declar

The article discusses the differences between unset() and unlink() functions in programming, focusing on their purposes and use cases. Unset() removes variables from memory, while unlink() deletes files from the filesystem. Both are crucial for effec


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SublimeText3 Linux new version
SublimeText3 Linux latest version

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

Dreamweaver CS6
Visual web development tools

Dreamweaver Mac version
Visual web development tools

WebStorm Mac version
Useful JavaScript development tools
