var people = [
{firstName : Thein, city : ny, qty : 5},
{firstName : Michael, city : ny, qty : 3},
{firstName : Bloom, city : nj, qty : 10}
];
var results=_.pluck(_.where(people, {city : ny}), 'firstName');
For example : I need firstName and qty.
To project to multiple properties, you need map, not pluck:
var results = _.map(
_.where(people, {city : ny}),
function(person) {
return { firstName: person.firstName, qty: person.qty };
}
);
[{firstName:Thein,qty:5},{firstName:Michael,qty:3}]
Note that, if you wanted to, you could create a helper method pluckMany that does the same thing as pluck with variable arguments:
// first argument is the source array, followed by one or more property names
var pluckMany = function() {
// get the property names to pluck
var source = arguments[0];
var propertiesToPluck = _.rest(arguments, 1);
return _.map(source, function(item) {
var obj = {};
_.each(propertiesToPluck, function(property) {
obj[property] = item[property];
});
return obj;
});
};
You can use the _.mixin function to add a pluckMany function to the _ namespace. Using this you can write simply:
var results = _.chain(people).where({city : ny}).pluckMany( firstName, qty).value();
