Jsoncpp simple example

1. Compile jsoncpp
Extract the source code package from (http://jsoncpp.sourceforge.net/unzip jsoncpp-src-0.5.0.tar.gz "and run it in the directory after its unzipping
$ Scons platform = Linux-gcc
The compiled library file has linux-gcc-4.4.2 and libjson_linux-gcc-4.4.2_libmt.so under its libs/libjson_linux-gcc-4.4.2_libmt.a directory. The header file is included in the extract directory. Install jsoncpp under $ home/usr/jsoncpp.

$ Mkdir ~ /Usr/jsoncpp

$ CP-r include ~ /Usr/jsoncpp

$ CP-r libs ~ /Usr/jsoncpp

2. Simple jsoncpp instance

1) deserialization of JSON objects
For example, the string sequence of a json object is as follows, where "array": [...] indicates the array in the JSON object:

{"Key1": "value1", "array": [{"key2": "value2" },{ "key2": "value3" },{ "key2 ": "value4"}]}

So how can we get the values of key1 and key2 respectively,CodeAs follows:

# Include <iostream> # include <string> # include "JSON/JSON. H "int main (void) {STD: String strvalue =" {\ "key1 \": \ "value1 \", \ "array \": [{\ "key2 \": \ "value2 \" },{ \ "key2 \": \ "value3 \" },{ \ "key2 \": \ "value4 \"}]} "; JSON: reader; JSON: Value value; If (reader. parse (strvalue, value) {STD: String out = value ["key1"]. asstring (); STD: cout <out <STD: Endl; const JSON: Value arrayobj = value ["array"]; (INT I = 0; I <arrayobj. size (); I ++) {out = arrayobj [I] ["key2"]. asstring (); STD: cout <out; if (I! = Arrayobj. Size ()-1) STD: cout <STD: Endl;} return 0 ;}
 

Compile the connection
$ G ++ jscpp1.cpp-I $ home/usr/jsoncpp/include /~ /Usr/jsoncpp/libs/linux-gcc-4.5.2/libjson_linux-gcc-4.5.2_libmt.a
$./A. Out
Value1
Value2
Value3
Value4

2) serialize a json object
Create a JSON object that contains arrays and serialize the JSON object into a string. The Code is as follows:

# Include <iostream> # include <string> # include "JSON/JSON. H "int main (void) {JSON: Value root; JSON: Value arrayobj; JSON: value item; For (INT I = 0; I <10; I ++) {item ["key"] = I; arrayobj. append (item);} root ["key1"] = "value1"; root ["key2"] = "value2"; root ["array"] = arrayobj; // root. tostyledstring (); STD: String out = root. tostyledstring (); STD: cout <out <STD: Endl; return 0 ;}
 

Compile the connection
$ G ++ jscpp2.cpp-I $ home/usr/jsoncpp/include /~ /Usr/jsoncpp/libs/linux-gcc-4.5.2/libjson_linux-gcc-4.5.2_libmt.a
$./A. Out
{
"Array ":[
{
"Key": 0
},
{
"Key": 1
},
{
"Key": 2
},
{
"Key": 3
},
{
"Key": 4
},
{
"Key": 5
},
{
"Key": 6
},
{
"Key": 7
},
{
"Key": 8
},
{
"Key": 9
}
],
"Key1": "value1 ",
"Key2": "value2"
}

Note: The above two codes are from the Internet, and these two instances are good, so they are borrowed here.

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1. compile jsoncpp