JavaScript | Add new attribute to JSON object

Last Updated : 25 Jun, 2021

The task is to add a JSON attribute to the JSON object. To do so, Here are a few of the most used techniques discussed.
Example 1: This example adds a prop_11 attribute to the myObj object via var key.

html

<!DOCTYPE HTML>
<html>

<head>
    <title>
        JavaScript 
      | Add new attribute to JSON object.
    </title>
</head>

<body style="text-align:center;"
      id="body">
    <h1 style="color:green;">  
            GeeksForGeeks  
        </h1>
    <p id="GFG_UP"
       style="font-size: 16px;
              font-weight: bold;">

    </p>

    <button onclick="gfg_Run()">
        Click here
    </button>
    <p id="GFG_DOWN" 
       style="color:green;
              font-size: 20px;
              font-weight: bold;">
    </p>

    <script>
        var el_up = 
            document.getElementById("GFG_UP");
        var el_down = 
            document.getElementById("GFG_DOWN");
        var myObj = {
            'prop_1': {
                'prop_12': 'value_12'
            }
        };
        el_up.innerHTML = JSON.stringify(myObj);

        function gfg_Run() {
            var key = "prop_11";
            myObj.prop_1[key] = "value_11";
            el_down.innerHTML = JSON.stringify(myObj);
        }
    </script>
</body>

</html>

Output:

Before clicking on the button:

After clicking on the button:

Example 2: This example adds a prop_11 attribute to the myObj with value value_11.

html

<!DOCTYPE HTML>
<html>

<head>
    <title>
        JavaScript
      | Add new attribute to JSON object.
    </title>
</head>

<body style="text-align:center;"
      id="body">
    <h1 style="color:green;">  
            GeeksForGeeks  
        </h1>
    <p id="GFG_UP"
       style="font-size: 16px;
              font-weight: bold;">

    </p>

    <button onclick="gfg_Run()">
        Click here
    </button>
    <p id="GFG_DOWN"
       style="color:green; 
              font-size: 20px; 
              font-weight: bold;">
    </p>

    <script>
        var el_up = 
            document.getElementById("GFG_UP");
        var el_down = 
            document.getElementById("GFG_DOWN");
        var myObj = {
            'prop_1': {
                'prop_12': 'value_12'
            }
        };
        el_up.innerHTML = JSON.stringify(myObj);

        function gfg_Run() {
            myObj.prop_1["prop_11"] = "value_11";
            el_down.innerHTML = JSON.stringify(myObj);
        }
    </script>
</body>

</html>

Output:

Before clicking on the button:

After clicking on the button:

JavaScript JSON Objects

PranchalKatiyar

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JavaScript | Add new attribute to JSON object

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