How to convert PHP array data to json

In PHP, you can use the json_encode() function to convert array data into json. The json_encode() function can json encode variables. If the conversion is successful, it will return json data, otherwise it will return false.

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

Now when we need to useajaxHow to convert php arrays to json when interacting with the background.

The powerful PHP has provided built-in functions:json_encode()andjson_decode(). It is easy to understand that json_encode() converts a PHP array into Json. On the contrary,json_decode()is to convert Json into a PHP array.

The specific form of Json is:

1. Object

The object is an unordered "'name/value' pair" gather. An object starts with "{" (left bracket) and ends with "}" (right bracket). Each "name" is followed by a ":" (colon); "name/value" pairs are separated by a "," (comma).

2. Array

An array is an ordered collection of values (value). An array starts with "[" (left bracket) and ends with "]" (right bracket). Values are separated by "," (comma).

Note: The two forms of objects and arrays are called differently in JS. Objects are called with "." and arrays are called with subscripts [0] and [1]. Also note that when passing a Json string, values of typestringmust be enclosed in quotes.

Instance 1:

$array = array("name" => "Eric","age" => 23); echo json_encode($array);

The program will print out:

{“name”:”Eric”,”age”:23}

Instance 2:

$array = array(0 => "Eric", 1 => 23); echo json_encode($array);

The program will output:

["Eric",23]

It can be seen from the above two examples that the two calls in js are different. The keys of the PHP array are all numbers, then json_encode() returns Json in the form of an array, if the keys of the PHP array are all strings. Then json_encode() will return Json in the form of an object.

In fact, as long as there is a key in the form of a string in the key of the PHP array, then json_encode() will return Json in the form of an object. This is not correct. Because, although no errors will occur in the PHP code, if such a Json is passed to a JS function, JS will treat the Json as an object, and it is impossible for an object to use numbers as attribute names. In other words, JS does not know what this is: user.0.username (the middle is the number zero)

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