var defaultValue = [{"pay_platform_id":0},{"pay_platform_id":1},{"pay_platform_id":3},{"pay_platform_id":4},{"pay_platform_id":5}];
var data = [{"channel":1, pay_platform_id:0, val:11}];
_.forEach(data, function (val) {
console.log(JSON.stringify(val))
val = _.orderBy(_.unionBy( defaultValue, val, 'pay_platform_id'), 'pay_platform_id');
con
});
console.log(JSON.stringify(data))
<div id='output'></div>