JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type="checkbox" name="foo" value="yes" />
    
    <input type="checkbox" name="foo2" value="yes" checked />
    
    <a id="submit">submit</a>
</form>

JavaScript

console.log($('form').serializeArray());

$('#submit').on('click', function(){
    var arr = $('form').serializeArray(),
        names = (function(){
            var n = [],
                l = arr.length - 1;
            for(; l>=0; l--){
                n.push(arr[l].name);
            }
            
            return n;
        })();
    
    $('input[type="checkbox"]:not(:checked)').each(function(){
        if($.inArray(this.name, names) === -1){
            arr.push({name: this.name, value: 'off'});
        }
    });
    
    console.log(arr);
});