Input Radio checked Attribute

HTML DOM Input Radio Obheto

Definition and Usage

checked Sets or returns the selected state of the radio button.

This attribute reflects the HTML checked attribute.

See also:

HTML Reference Manual:HTML <input> checked 属性

Example

Example 1

Select and deselect a specified radio button:

function check() {
  document.getElementById("red").checked = true;
}
function uncheck() {
  document.getElementById("red").checked = false;
}

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Example 2

Check if the radio button is selected:

var x = document.getElementById("myRadio").checked;

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Example 3

Use radio buttons to convert text in input fields to uppercase:

document.getElementById("fname").value = document.getElementById("fname").value.toUpperCase();

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Example 4

Radio buttons in the 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 coffee with: " + txt;

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Syntax

Return the checked attribute:

radioObject.checked

Set the checked attribute:

radioObject.checked = true|false

属性值

值 描述
true|false

规定是否应选中单选按钮。

  • true - 单选按钮被选中
  • false - 默认。未选中单选按钮

技术细节

返回值： 布尔值，如果单选按钮被选中则返回 true；否则返回 false。

浏览器支持

Chrome Edge Firefox Safari Opera
Chrome Edge Firefox Safari Opera
支持 支持 支持 支持 支持

HTML DOM Input Radio Obheto