Jquery checkbox checked when page loads

Question

The script is working fine however I am wondering if there is a way to avoid the repetition in the code (DRY method).

Demo

JS code:

// Checkbox checked and input disbaled when page loads

$('#checkbox').prop('checked', true);

if ($('#checkbox').is(':checked') == true) {
    $('#textInput').prop('disabled', true);
}


// Enable-Disable text input when checkbox is checked or unchecked

$('#checkbox').change(function() {
    if ($('#checkbox').is(':checked') == true) {
        $('#textInput').prop('disabled', true);
    } else {
        $('#textInput').val('').prop('disabled', false);
    }
});

Answer 1

If you can't set the attributes by default in HTML:

// Checkbox checked and input disbaled when page loads
$('#checkbox').prop('checked', true);

// Enable-Disable text input when checkbox is checked or unchecked
$('#checkbox').on('change', function() {
    var value = this.checked ? $('#textInput').val() : '';
    $('#textInput').prop('disabled', this.checked).val(value);
}).trigger('change');

Demo: http://jsfiddle.net/tusharj/t01a9cxL/1/

Answer 2

If every time the page is loaded you want the check box to be checked and the text box to be disabled it's better to do it in HTML

HTML

<input type="checkbox" id="checkbox" checked="true" />
<input type="text" id="textInput" disabled=""/>

JavaScript

// Enable-Disable text input when checkbox is checked or unchecked

$('#checkbox').change(function() {
    if ($('#checkbox').is(':checked') == true) {
        $('#textInput').prop('disabled', true);
    } else {
        $('#textInput').val('').prop('disabled', false);
    }
});