Some minor explanation: - We use Array.prototype.filter() function to filter out the keys that start with `imageIds2 - We use Array.prototype.reduce() to convert an array of filtered keys into an object of key-value pairs. For that we use the initial value of {} (an empty object), fill it and return from every execution step.

object_filter.js

var data = {
    title: 'fsdfsd',
    titleZh: 'fsdfsd',
    body: 'fsdf',
    bodyZh: 'sdfsdf',
    imageIds: '/uploads/tmp/image-3.png',
    imageIdsZh: '' 
};

var z = Object.keys(data).filter(function(k) {
    return k.indexOf('imageIds') == 0;
}).reduce(function(newData, k) {
    newData[k] = data[k];
    return newData;
}, {});

console.log(z);