Valid json check in C language

I have searched a lot in google, I want to programatically check if the string below is valid json in C.How to do that? I am currently using json-c library.

    char * string = "{
                  number1 : 100,
                number2 : 10,
                files : [ c , c++, java,PHP,java,PHP ],
                random: [123567876523333,908,988]
                }";

the library has no function to check if the string is valid json. Thanks in Advance.