55 lines
1.3 KiB
Markdown
55 lines
1.3 KiB
Markdown
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---
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title: Working With JSON APIs
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localeTitle: 使用JSON API
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---
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## 使用JSON API
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JSON的一个常见用途是从Web服务器读取数据，并在网页中显示数据。
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本章将教您如何在客户端和PHP服务器之间交换JSON数据。
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### PHP文件
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PHP有一些内置函数来处理JSON。
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可以使用PHP函数`json_encode()`将PHP中的对象转换为JSON：
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```php
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<?php
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$myObj->name = "John";
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$myObj->age = 30;
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$myObj->city = "New York";
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$myJSON = json_encode($myObj);
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echo $myJSON;
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?>
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```
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[试试吧](https://www.w3schools.com/js/showphp.asp?filename=demo_file)
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### 客户端JavaScript
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这是客户端上的JavaScript，使用AJAX调用从上面的示例请求PHP文件：
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#### 例
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使用JSON.parse（）将结果转换为JavaScript对象：
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```js
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var xmlhttp = new XMLHttpRequest();
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xmlhttp.onreadystatechange = function() {
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if (this.readyState == 4 && this.status == 200) {
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var myObj = JSON.parse(this.responseText);
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document.getElementById("demo").innerHTML = myObj.name;
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}
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};
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xmlhttp.open("GET", "demo_file.php", true);
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xmlhttp.send();
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```
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[试试吧](https://www.w3schools.com/js/tryit.asp?filename=tryjson_php_simple)
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### 更多信息：
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* 有关更多信息， [请查看此链](https://www.w3schools.com/js/js_json_php.asp)
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