Ways to check if an input Checkbox is checked

checked_input_check_with_attr_jquery.js

var myCheckbox = $('#my_checkbox:checked');

//Checando com o selector :checked
if (myCheckbox.val()) {
  console.log('Checked!');
} else {
  console.log('Not checked!');
}

checked_input_check_with_is_jquery.js

var myCheckbox = $('#my_checkbox');

//Checando com a função is
if (myCheckbox.is(':checked')) {
  console.log('Checked!');
} else {
  console.log('Not checked!');
}

checked_input_check_with_javascript.js

//Checando com a propriedade cheched do elemento com JavaScript 
var myCheckbox = $('#my_checkbox');

if (myCheckbox[0].checked) {
  console.log('Checked!');
} else {
  console.log('Not checked!');
}

checked_input_check_with_prop_jquery.js

var myCheckbox = $('#my_checkbox');

//Checando com a função PROP
if (myCheckbox.prop('checked')) {
  console.log('Checked!');
} else {
  console.log('Not checked!');
}