var jsonStringfy = JSON.stringify(this.jsonObj);
console.log(jsonStringfy) // {"name":"leinov", "sex":"famle", "address":"beijing"}
console.log(typeof jsonStringfy) //string
JSON.parse:
var jsonParse = JSON.parse(jsonStringfy)
console.log(jsonParse) // {name: "leinov", sex: "famle", address: "beijing"}
console.log(typeof jsonParse) //object