ee.FeatureCollection.makeArray

Add a 1-D Array to each feature in a collection by combining a list of properties for each feature into a 1-D Array. All of the properties must be numeric values. If a feature doesn't contain all of the named properties, or any of them aren't numeric, the feature will be dropped from the resulting collection.
UsageReturns
FeatureCollection.makeArray(properties, name)FeatureCollection
ArgumentTypeDetails
this: collectionFeatureCollectionThe input collection from which properties will be selected.
propertiesListThe properties to select.
nameString, default: "array"The name of the new array property.

Examples

Code Editor (JavaScript)

// FeatureCollection of power plants in Belgium.
var fc = ee.FeatureCollection('WRI/GPPD/power_plants')
            .filter('country_lg == "Belgium"');

// A list of feature properties to combine into an array
// (power generation by year).
var properties = ['gwh_2013', 'gwh_2014', 'gwh_2015', 'gwh_2016'];

// Add array of power-generation-by-year property to features.
fc = fc.makeArray(properties, 'gwh_by_year');

print('FeatureCollection with array of selected properties added', fc);
print('See example of new "gwh_by_year" property', fc.first().toDictionary());