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🗣 Wd提问: php json

🤖 Ai回答:
PHP provides built-in functions to work with JSON (JavaScript Object Notation), a lightweight data interchange format、Here are the most commonly used PHP functions for handling JSON:

🔹 1、`json_encode()` – Convert PHP data to JSON

Converts a PHP variable (array, object, etc.) into a JSON string.

php
$data = [
'name' = 'John',
'age' = 30,
'city' = 'New York'
];

$jsonString = json_encode($data);
echo $jsonString;
// Output: {name:John,age:30,city:New York}

Options:
`JSON_PRETTY_PRINT` – Formats output with indentation.
`JSON_UNESCAPED_UNICODE` – Don't escape Unicode characters.
`JSON_UNESCAPED_SLASHES` – Don't escape slashes.

php
$prettyJson = json_encode($data, JSON_PRETTY_PRINT);
echo $prettyJson;

🔹 2、`json_decode()` – Convert JSON to PHP data

Parses a JSON string and converts it into a PHP array or object.

php
$jsonString = '{name:Alice,age:25,city:London}';

// Decode as associative array
$data = json_decode($jsonString, true);
print_r($data);
// Output: Array ( [name] = Alice [age] = 25 [city] = London )

// Decode as object
$obj = json_decode($jsonString);
echo $obj-name; // Output: Alice

If JSON is invalid, `json_decode()` returns `null`.

🔹 3、Check for Errors

Always check if JSON encoding/decoding was successful.

php
$json = json_encode($data);

if (json_last_error() === JSON_ERROR_NONE) {
echo Success!;
} else {
echo Error: 、json_last_error_msg();
}

For decoding:
php
$result = json_decode($jsonString, true);

if ($result === null && json_last_error() !== JSON_ERROR_NONE) {
echo JSON decode error: 、json_last_error_msg();
}

🔹 Example: Full Workflow

php
<?php
// PHP array
$user = [
'id' = 1,
'name' = 'Bob',
'email' = 'bob@65.hk'
];

// Encode to JSON
$json = json_encode($user, JSON_PRETTY_PRINT);
echo $json;

// Decode back
$decoded = json_decode($json, true);
var_dump($decoded);
?

✅ Tips

Use `json_decode(..., true)` when you want arrays instead of objects.
Always validate JSON using `json_last_error()` after operations.
JSON only supports basic data types: strings, numbers, booleans, arrays, objects, and `null`.

Let me know if you want examples for files, APIs, or working with nested structures!

Ai作答

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