The background receives the post data passed by the fetch

fetch Official website post Data is transmitted by JSON.stringify() In the form of ：

fetch('http://www.tingchunyu.com/test/fetch_test/fetch_getuser_test.php', {
    body: JSON.stringify({id:666}),
    headers: {
        'content-type': 'application/json'
    },
    method: 'POST',
})
    .then(response => {
        if (response.ok){// Determine if the request is successful 
            return response.json()
        }
        throw new Error(' Request error ')
    })
    .then(data=>{
        console.log(data)
    })
    .catch(error => {
        console.log(error)
    })

But like the above, the background always receives variables in the previous way null. The reason for this is that the data submitted to the server is json data , Not traditional formdata. As shown in the figure below ：

Therefore, there are two solutions for the background to receive data

Put the above code body Make the following changes to the format of

body: JSON.stringify({id:666}) It is amended as follows  body: 'id=666'

// If there are multiple parameters, you can use "&" Connect Such as ：body: 'id=666&type=0'

But if there are many parameters to be passed in this way, it will be a bit troublesome .

The second method , Keep the above code unchanged . Modify the method of background receiving parameters . With PHP For example ：

// take $_POST['id'] Change to the following method

$data = json_decode(file_get_contents('php://input'),true);
$id = $data['id'];// So you can receive ID 了