String to JSON Object using backslash escapes (Encode and Decode)

http://json.org
A string is a sequence of zero or more Unicode characters, wrapped in double quotes, using backslash escapes. A character is represented as a single character string. A string is very much like a C or Java string.

In ECMA262 version 5

Javascript Object to JSON	JSON to Javascript Object
JSON.stringify()	JSON.parse()

 <script type="text/javascript">
  var j='{"acct_id":100001,"acct_name":"na\\"me","email":"Jet\'mail"}';
  var o=JSON.parse(j);
  alert(o.acct_id+o.acct_name+o.email);
  var jj='[{"acct_id":100000,"acct_name":"name0","email":"Jemail0"}]';
   var oo=[];
   oo=JSON.parse(jj);
  alert(oo[0].acct_id+oo[0].acct_name+oo[0].email);
//------
        function getJsonObjLength(jsonObj){
            var l=0;for(var i in jsonObj){l++;}return l;
        }
        var myObj={"A0E":{"1":1}};
        for(x in myObj){
            console.log(x);//A0E
        }
        console.log(getJsonObjLength(myObj));//1
        for(x in myObj){
            console.log(myObj[x]);//Object{1:1}
        }
        console.log(myObj["A0E"]);//Object{1:1}
        
        var obj =new Object();
        obj.code="001";obj.name="hello";
        var str=JSON.stringify(obj);
        console.log(str);//{"code":"001","name":"hello"}

        var jsonArr=new Array();
        for(var i=0;i<2;i++){
            var obj=new Object();
            obj.title="title"+i;
            obj.value=i;
            jsonArr.push(obj);
        }
        var str=JSON.stringify(jsonArr);
        console.log(str);//[{"title":"title0","value":0},{"title":"title1","value":1}]
        var jj='[{"acct_id":100000,"acct_name":"name0","email":"Jemail0"}]';
        var jStr1='{"code":"001"}';
        jStr1="{\"code\":\"001\"}";
        var jO=JSON.parse(jStr1);
        console.log(jO["code"]); // 001
</script>

Exception: SyntaxError:Invalid 
The name of the name/value pairs in JSON must be wrapped in double quotes. If it were otherwise, JSON.parse will throw a "sytaxError:Invalid" exception.

<script type="text/javascript">
try{
  var j='{acct_id:100001,"acct_name":"na\\"me","email":"Jemail"}';//acct_id is not in double quotes.
  var o=JSON.parse(j);//will throw an exception
  alert(o.acct_id+o.acct_name+o.email);
  }catch(e){
    var j='{acct_id:100001,"acct_name":"na\\"me","email":"Jemail"}';
   var o;
   eval("o="+j);
  alert("In Exception: \r\n"+o.acct_id+o.acct_name+o.email);
  }
  </script>

Encode and Decode

Encode	Decode	unEncode	Unencode total
encodeURIComponent ：- >UTF-8 or  $.param() in jQuery https://api.jquery.com/jQuery.param/	decodeURIComponent	!， ‘，(，)，*，-，.，_，~，0-9，a-z，A-Z	71
encodeURI ：- > UTF-8	decodeURI	!，#，$，&，’，(，)，*，+，,，-，.，/，:，;，=，?，@，_，~，0-9，a-z，A-Z	82
escape ：- > Unicode	unescape	*，+，-，.，/，@，_，0-9，a-z，A-Z	69