Example
Check and un-check a specific radio button:
function check() {
document.getElementById("red").checked = true;
}
function uncheck() {
document.getElementById("red").checked = false;
}
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Definition and Usage
The checked property sets or returns the checked state of a radio button.
This property reflects the HTML checked attribute.
Browser Support
The checked property is supported in all major browsers.
Syntax
Return the checked property:
radioObject.checked
Set the checked property:
radioObject.checked=true|false
Property Values
| Value | Description |
|---|---|
| true|false |
Specifies whether a radio button should be checked or not.
|
Technical Details
| Return Value: | A Boolean, returns true if the radio button is checked, and false if the radio button is not checked |
|---|
More Examples
Example
Find out if a radio button is checked or not:
var x = document.getElementById("myRadio").checked;
The result of x will be:
true
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Example
Use a radio button to convert text in an input field to uppercase:
document.getElementById("fname").value = document.getElementById("fname").value.toUpperCase();
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Example
Several radio buttons in a form:
var coffee = document.forms[0];
var
txt = "";
var i;
for (i = 0; i < coffee.length; i++) {
if
(coffee[i].checked) {
txt = txt +
coffee[i].value + " ";
}
}
document.getElementById("order").value = "You ordered a coffee with: " + txt;
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Related Pages
HTML reference: HTML <input> checked attribute
< Input Radio Object