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How to store data as JSON like a database, so that when a user registers the information should be stored in a variable?

Example:

My HTML form consists of input text fields firstname, lastname. Clicking the register button of the form should store the values of firstname and lastname in a variables.

How can I do this:

 var txt = '{"employees":[' +
   '{"firstName":"John","lastName":"Doe" },' +
    '{"firstName":"Anna","lastName":"Smith" },' +
     '{"firstName":"Peter","lastName":"Jones" }]}';

How to store data as JSON like a database, so that when a user registers the information should be stored in a variable?

Example:

My HTML form consists of input text fields firstname, lastname. Clicking the register button of the form should store the values of firstname and lastname in a variables.

How can I do this:

 var txt = '{"employees":[' +
   '{"firstName":"John","lastName":"Doe" },' +
    '{"firstName":"Anna","lastName":"Smith" },' +
     '{"firstName":"Peter","lastName":"Jones" }]}';

• javascript
• jquery
• json

Share Improve this question Follow edited Jan 12, 2016 at 16:03 Henry Lynx 1,12911 gold badge2020 silver badges4242 bronze badges asked Aug 26, 2013 at 12:23 Joshna GunturuJoshna Gunturu 16111 gold badge22 silver badges1414 bronze badges 4

• you can use var json = JSON.parse(txt) – Arun P Johny Commented Aug 26, 2013 at 12:24
• 2 @ArunPJohny I think OP is asking for the other direction – Paul S. Commented Aug 26, 2013 at 12:24
• Is there a reason you want to use JSON? You cannot really process it further since it is just text. A simple object or array would be more appropriate. – Felix Kling Commented Aug 26, 2013 at 12:38
• i did not have much knowledge on JSON can you please tell me a good source for it @ArunPJohny – Joshna Gunturu Commented Aug 26, 2013 at 12:40

Add a ment  | 

4 Answers 4

Sorted by: Reset to default 2

Sounds like you want to go from values in HTML to a JSON string. Assuming <form> looks like this

<form>
    <input type="text" name="nm1[]"/><input type="text" name="nm2[]"/>
    <input type="text" name="nm1[]"/><input type="text" name="nm2[]"/>
</form>

You can use getElementsByName twice, build an Object and JSON.stringify it

var nm1 = document.getElementsByName('nm1[]'),
    nm2 = document.getElementsByName('nm2[]'),
    i, o = {
        employees: []
    };
for (i = 0; i < nm1.length; ++i) {
    if (nm1[i].value && nm2[i].value)
        o.employees.push({
            firstName: nm1[i].value,
            lastName: nm2[i].value
        });
}
JSON.stringify(o);

DEMO (open console)

You can add data to the actual data structure by appending it to the employees array like

dataobj.employees.push({"firstName":$('input[name=firstn]').val(),
                        "lastName":$('input[name=lastn]').val() });

Of course, this requires that the JSON was parsed into the dataobj in the first place. It must be serialized again if you want to send it by GET. But it can be POSTed directly as a data object!

You can of course also start with an empty array, initializing dataobj like

var dataobj={ employee: [] };

before the above uptdating mand es into action.

A very late edit ...

Just in case there should be multiple firstname / lastname input fields, then the following will do a "much better" job (as it will have a look at all fields and collect only those where at least one of the names is set):

var dataobj={employees:[]};
function shw(){
  $('#out').text(JSON.stringify(dataobj).replace(/{/g,'\n{'));}
$(function(){
  $('#clr').click(function(){dataobj.employees=[];shw()});
  $('#go').click(function(){
   var ln=$('input[name=lastn]').toArray();     // ln: JS-Array of DOM elements
   $('input[name=firstn]').each(function(i,fn){ // for each fn DOM-element ...
    var f=fn.value,l=ln[i].value;               // get values as strings
    if (f+l>'') dataobj.employees.push({firstName:f,lastName:l}); // push name object
   });shw();})
  shw();
});

<script src="https://ajax.googleapis./ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" name="firstn" value="John"><input type="text" name="lastn" value="Doe"><br>
<input type="text" name="firstn" value="Anna"><input type="text" name="lastn" value="Smith"><br>
<input type="text" name="firstn" value="Peter"><input type="text" name="lastn" value="Jones">
<input type="button" id="go" value="append names">
<input type="button" id="clr" value="clear">
<pre id="out"></pre>

Easily use Jquery

var jsonArray;
jsonArray.push($("#firstname").val();
jsonArray.push($("#lastname").val();
var myJsonString = JSON.stringify(jsonArray);

You can use the push method of array to push JSON data. This is shown here - appending-to-a-json-object. Before the data needs to be submitted (say to process.php), stringify it.

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