LoDash: Get an array of values from an array of object properties

问题

I'm sure it's somewhere inside the LoDash docs, but I can't seem to find the right combination.

var users = [{
      id: 12,
      name: Adam
   },{
      id: 14,
      name: Bob
   },{
      id: 16,
      name: Charlie
   },{
      id: 18,
      name: David
   }
]

// how do I get [12, 14, 16, 18]
var userIds = _.map(users, _.pick('id'));

回答1:

Since version v4.x you should use _.map:

_.map(users, 'id'); // [12, 14, 16, 18]

this way it is corresponds to native Array.prototype.map method where you would write (ES2015 syntax):

users.map(user => user.id); // [12, 14, 16, 18]

Before v4.x you could use _.pluck the same way:

_.pluck(users, 'id'); // [12, 14, 16, 18]

回答2:

With pure JS:

var userIds = users.map( function(obj) { return obj.id; } );

回答3:

In the new lodash release v4.0.0 _.pluck has removed in favor of _.map

Then you can use this:

_.map(users, 'id'); // [12, 14, 16, 18]

You can see in Github Changelog

回答4:

And if you need to extract several properties from each object, then

let newArr = _.map(arr, o => _.pick(o, ['name', 'surname', 'rate']));

回答5:

If you are using native javascript then you can use this code -

let ids = users.map(function(obj, index) {

    return obj.id;
})

console.log(ids); //[12, 14, 16, 18]

回答6:

This will give you what you want in a pop-up.

for(var i = 0; i < users.Count; i++){
   alert(users[i].id);  
}

来源：https://stackoverflow.com/questions/28354725/lodash-get-an-array-of-values-from-an-array-of-object-properties