JSON encoding and decoding in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does JSON encoding mean in PHP?

JSON encoding means converting PHP data like arrays or objects into a JSON string format that can be easily shared or stored.

beginner

Which PHP function is used to convert a PHP array into a JSON string?

The function json_encode() converts a PHP array or object into a JSON string.

beginner

What does JSON decoding mean in PHP?

JSON decoding means converting a JSON string back into a PHP variable like an array or object.

beginner

Which PHP function is used to convert a JSON string into a PHP variable?

The function json_decode() converts a JSON string into a PHP array or object.

intermediate

What does the second parameter of json_decode() control?

The second parameter controls if the JSON string is decoded into an associative array (true) or an object (false, default).

Which function converts a PHP array to a JSON string?

A json_encode()

B json_decode()

C json_parse()

D json_to_array()

json_encode() converts PHP data into a JSON string.

What does json_decode() return by default?

A A PHP associative array

B A PHP object

C A JSON string

D An error

By default, json_decode() returns a PHP object unless the second parameter is set to true.

How do you get an associative array from json_decode()?

A Set second parameter to true

B Set second parameter to false

C Use json_encode() instead

D Use json_parse()

Passing true as the second parameter to json_decode() returns an associative array.

What type of data can json_encode() convert?

A Only strings

B Only numbers

C Arrays and objects

D Only booleans

json_encode() can convert PHP arrays and objects into JSON strings.

What happens if json_decode() receives invalid JSON?

A Returns the original string

B Throws an exception

C Returns false

D Returns null

json_decode() returns null if the JSON string is invalid.

Explain how to convert a PHP array to JSON and back to a PHP array.

Think about the functions and parameters needed for encoding and decoding.

Describe the difference between decoding JSON to an object versus an associative array in PHP.

Focus on the second parameter of json_decode().