JSON (note)

JSON (JavaScript Object Notation), is a lightweight data interchange format.

Four basic rules of syntax:

1. The parallel data is separated by commas (",").

2. The map is represented by a colon (":").

3. The data set (array) in parallel is denoted by square brackets ("[]").

4. The mapped collection (object) is represented by braces ("{}").

Cases:

"Beijing's area is 16800 square kilometers, the resident population is 16 million people." The area of Shanghai is 6400 square kilometers, the resident population is 18 million. ”

After converting to JSON format:

[

{"City": "Beijing", "area": "16800", "Population": "1600"},

{"City": "Shanghai", "area": "6400", "Population": "1800"}

]

Advantages: The data format is simple, easy to read and write, the format is compressed, occupy small bandwidth. Multi-lingual support.

Disadvantage: Required character encoding must be Unicode and can be used under any character set. be highly constrained. The grammar is too rigorous.

Important functions of PHP operation JSON:

Encryption: Json_encode ()

Decryption: Json_decode ()

Json_encode ()

One-dimensional arrays, multidimensional arrays to JSON conversions

Object into the JSON data format, converting only the public property values.

Json_decode ()

Convert JSON to object type and array type:

The JSON is converted to an array, requiring the second argument to be true. $jsonArray = Json_decode ($jsonStr, True).

The default conversion is object type. $json = Json_decode ($JSONSTR).

JSON (note)