var formFields = [
{value:"123",category:[1,2]}
];
formFields.map(function(ele){
console.log(ele.category);
if( $.inArray(3,ele.category)){
console.log("hai");
}else{
console.log("nahi hai");
}
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
&#13;