ajax3—php (29), ajax3php29_PHP tutorial

ajax3—php (29), ajax3php29

1. Application of json in Ajax

For processing of large batches of data:

1) xml

2) json

1. About json

An object is an unordered collection of attributes

In js, you can use {} to simulate an unordered collection of attributes

1. About json in php

Currently, most ajax programs use json objects as data transfer methods, so many languages ​​have built-in support for json objects. In php, there are two functions for encoding and decoding json

l string json_encode ( mixed $value )

Generate string in json format

l mixed json_decode ( string $json [, bool])

Parse json

The second parameter indicates whether to parse into an array or an object. The default is false, which means parsing into an object

1) json_encode

If you want to get data in json format, you must first get an array or object

2) json_decode

3) json_decode

Json currently only supports utf-8 format

3. Ajax uses json

Example 1: Using json to return four arithmetic operations of two numbers

Server code:

Example 2: Return multiple pieces of data from the server

Ajax program:

Php program: