Parsing the JSON object in salesforce

 
For example- Its a JSON output. We have to parse this.
{
    "CompanyContacts": [
        {
            "contact": "pn0",
            "postalcode": "0",
            "contactnumber": "pc0"
        },
        {
            "contact": "pn1",
            "postalcode": "1",
            "contactnumber": "pc1"
        },
        {
            "contact": "pn2",
            "postalcode": "2",
            "contactnumber": "pc2"
        }
    ]
}

 
public class CompanyContacts
{
     public List CompanyContacts;
}

public class CompanyContactsWrapper
{
     public String contact;
     public String postalcode;
     public String contactnumber;
}

then deserialize your JSON string in a new instace of the classes you created.

 
CompanyContacts.companycontacts = (CompanyContacts)JSON.deserialize(jsonstring, CompanyContacts.class);