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This article mainly introduces "how to understand the coding and transcoding of JSON in PHP". In daily operation, I believe many people have doubts about how to understand the coding and transcoding of JSON in PHP. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful to answer the doubts of "how to understand the coding and transcoding of JSON in PHP". Next, please follow the editor to study!

What is JSON?

JSON is mainly used to transfer data, it is a lightweight data exchange format, it can be completely different from the PHP programming language to store and represent data.

It is relatively easy to read and write, while JSON for machine parsing and generation is also relatively simple, through JSON can effectively improve the efficiency of data transmission.

We already have a built-in JSON extension in PHP, so let's take a look at the JSON function in PHP and how to use the PHP language to encode JSON objects.

Json_encode () JSON coding

Json_encode () in PHP is used to JSON encode variables, and the basic syntax format of this function is as follows:

String json_encode ($value [, $options = 0])

It should be noted that if you run the json_encode () function successfully, the result returned is the data of JSON. If you run the error, the result returned is false.

The parameter $value represents the value that needs to be encoded. What is special about json_encode () is that only the data encoded by UTF-8 is valid for this function. The parameter options represents a binary mask made up of constants: JSON_HEX_QUOT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_NUMERIC_CHECK,JSON_PRETTY_PRINT, JSON_UNESCAPED_SLASHES, JSON_FORCE_OBJECT.

Next, let's take a look at the use of the json_encode () function in PHP, that is, converting the array elements of PHP into data in JSON format. The example is as follows:

Output result:

From the above example, we can see that the array elements of PHP can be converted into JSON-appropriate data through json_encode (), and only UTF-8-encoded data is valid for this function.

The above example converts an one-dimensional array in PHP. Next, let's take a look at the result of multi-dimensional array conversion. The example is as follows:

Output result:

The above example converts the array elements in PHP through functions. Next, let's take a look at the data that converts the PHP object to JSON format. The example is as follows:

Output result:

Let's look at another example:

Output result:

Thus we complete the conversion of objects in PHP to JSON format through the json_encode () function.

Json_decode () JSON decoding

PHP can use the json_decode () function to convert the character exchange of JSON format to the variable format of PHP, that is, decoding. Let's take a look at the basic syntax format of the json_decode () function. The example is as follows:

Mixed json_decode ($json [, $assoc = false [, $depth = 512 [, $options = 0])

It should be noted that the parameter json_string represents the JSON format string that needs to be converted, that is, the decoded string, like the json_encode () function, the decoded data must also be UTF-8 encoded data; the parameter assoc indicates that when the parameter is true, the returned result is an array, and when the parameter is false, the returned result is an object.

The parameter depth represents a parameter of integer type, and the parameter options represents a binary mask. Unlike json_encode (), this function currently does not support so many, only JSON_BIGINT_AS_STRING.

Next, let's take a look at how to decode PHP through an example, as follows:

Output result:

Through the above example, we can see that the JSON is decoded by json_decode (). The above is decoded into an array. Let's take a look at the decoded object. The example is as follows:

Output result:

Therefore, we complete the encoding and decoding of PHP data and JSON through json_encode () function and json_decode () function.

At this point, the study on "how to understand the coding and transcoding of JSON in PHP" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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