The case is simple - I\'ve got a following object:
Object {1: false, 2: true, 3: false, 4: false, 5: false, 6: false, 7: false, 8: true, 12: false, 13: false, 14
var data = {1: false, 2: true, 3: false, 4: true}; var filteredIds = _.filter(_.keys(data), function (key) { return data[key]; }); // result [2, 4] var rejectedIds = _.reject(_.keys(data), function (key) { return data[key]; }); // result [1, 3]