Merge property from an array of objects into another based on property value lodash

Question

I have 2 arrays of objects, they each have an id in common. I need a property from objects of array 2 added to objects array 1, if they have matching id<

Answer 1

You can use pick to get only the properties you want before merging:

var result = _.merge( arr1, _.map( arr2, function( obj ) {
    return _.pick( obj, 'id', 'eyeColour' );
}));