Input Checkbox checked Attribute

HTML DOM Input Checkbox Obhekto

Definition and Usage

checked Sets or returns the checked state of the checkbox.

This attribute reflects the HTML checked attribute.

See also:

HTML Reference Manual:HTML <input> checked 属性

Example

Example 1

Set the checked state of the checkbox:

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

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Example 2

Check if the checkbox is selected:

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

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Example 3

Use checkboxes to convert text in input fields to uppercase:

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

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Example 4

Several checkboxes 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:

checkboxObject.checked

Set the checked attribute:

checkboxObject.checked = true|false

属性值

值 描述
true|false

规定是否应选中复选框。

  • true - 复选框被选中
  • false - 默认。复选框未选中

技术细节

返回值： 布尔值，如果选中复选框，则返回 true，如果未选中复选框，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 Checkbox Obhekto