如果选中一个复选框，如何从多个复选框中获取值​？

var checkboxes = document.getElementsByName('checkboxName');
var selectedValues = [];

for (var i = 0; i < checkboxes.length; i++) {
    if (checkboxes[i].checked) {
        selectedValues.push(checkboxes[i].value);
    }
}

console.log(selectedValues);

var selectedValues = [];

$('input[name="checkboxName"]:checked').each(function() {
    selectedValues.push($(this).val());
});

console.log(selectedValues);

<form id="myForm">
    <input type="checkbox" name="checkboxName" value="value1">
    <input type="checkbox" name="checkboxName" value="value2">
    <input type="checkbox" name="checkboxName" value="value3">
    <input type="submit" value="Submit">
</form>