HTML | DOM Input Radio defaultvalue Property

Last Updated : 23 Sep, 2022

The Input Radio defaultValue Property in HTML DOM is used to set or return the default value of a Radio field. This property is used to reflect the HTML value attribute. The main difference between the default value and value is that the default value indicate the default value and the value contains the current value after making some changes. This property is useful to find out whether the Input radio field has been changed or not.

Syntax:

It returns the defaultValue property.

RadioObject.defaultValue

It is used to set the defaultValue property.

RadioObject.defaultValue = value

Property Values: It contains single property value value which defines the default value for Input Radio field.

Return Value: It returns a string value which represents the default value of the Input Radio field.

Example 1: This example illustrates how to return Input radio defaultValue Property.

HTML

<!DOCTYPE html>
<html>
<head>
    <style>
        body {
            text-align: center;
        }
        h1 {
            color: green;
        }
    </style>
</head>
<body>
    <h1>GeeksforGeeks</h1>
    <h2>
        HTML DOM Input Radio defaultvalue Property
    </h2>
    Radio Button:
    <input type="radio" checked=true id="radioID"
        value="Geeks_radio">
    <br><br>
    <button onclick="GFG()">
        Click!
    </button>
    <p id="GFG" style=
        "font-size:25px;color:green;">
    </p>
    <script>
        function GFG() {
 
            // Returning Input Radio defaultvalue Property
            var x = document.getElementById(
                    "radioID").defaultValue;
             
            document.getElementById(
                    "GFG").innerHTML = x;
        }
    </script>
</body>
</html>

Output:

Before Clicking On Button:

After Clicking On Button:

Example 2: This example illustrates how to set Input radio defaultValue Property.

HTML

<!DOCTYPE html>
<html>
<head>
    <style>
        body {
            text-align: center;
        }
        h1 {
            color: green;
        }
    </style>
</head>
<body>
    <h1>GeeksforGeeks</h1>
    <h2>
        HTML DOM Input Radio defaultvalue Property
    </h2>
    Radio Button:
    <input type="radio" checked=true id="radioID"
                value="Geeks_radio">
    <br><br>
    <button onclick="GFG()">
        Click!
    </button>
     
    <p id="GFG" style=
        "font-size:25px;color:green;">
    </p>
    <script>
        function GFG() {
 
            // Setting Input Radio defaultvalue Property
            var x = document.getElementById("radioID"
                    ).defaultValue = "GeeksForGeeks";
             
            document.getElementById("GFG").innerHTML
                    = x;
        }
    </script>
</body>
</html>