I've an array like:
ids = [1,3,5];
and another array like:
items: [
{id: 1, name: 'a'},
{id: 2, name: 'b'},
{id: 3, name: 'c'},
{id: 4, name: 'd'},
{id: 5, name: 'e'},
{id: 6, name: 'f'}
];
What I want is another array like:
array = [{id: 1, name: 'a'}, {id: 3, name: 'c'}, {id: 5, name: 'e'}];
I can't get my head around it. so far i tried like:
console.log(R.filter(R.propEq('id', <donnow what shud be here>), items);
console.log( R.pick(ids)(items))
If you still want to do with Ramda:
const ids = [1,3,5];
const items = [
{id: 1, name: 'a'},
{id: 2, name: 'b'},
{id: 3, name: 'c'},
{id: 4, name: 'd'},
{id: 5, name: 'e'},
{id: 6, name: 'f'}
];
console.log(
R.filter(R.compose(R.flip(R.contains)(ids), R.prop('id')), items)
);<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.26.1/ramda.min.js"></script>You can use .filter and .indexOf. Note these are ECMA5 methods for Arrays, and will not work in IE8.
var ids = [1, 3, 5];
var items = [
{id: 1, name: 'a'},
{id: 2, name: 'b'},
{id: 3, name: 'c'},
{id: 4, name: 'd'},
{id: 5, name: 'e'},
{id: 6, name: 'f'}
];
var filtered = items.filter(function(obj) {
return ids.indexOf(obj.id) > -1;
});
console.log(filtered); // [{id: 1, name: 'a'}, {id: 3, name: 'c'}, {id: 5, name: 'e'}];
Or may be one liner without Ramda
items.filter(x=>ids.includes(x.id))
I suggest to use a hash table for faster lookup.
var ids = [1, 3, 5],
items = [{id: 1, name: 'a'}, {id: 2, name: 'b'}, {id: 3, name: 'c'}, {id: 4, name: 'd'}, {id: 5, name: 'e'}, {id: 6, name: 'f'} ],
filtered = items.filter(function(obj) {
return this[obj.id];
}, ids.reduce(function (r, a) {
r[a] = true;
return r;
}, Object.create(null)));
document.write('<pre>' + JSON.stringify(filtered, 0, 4) + '</pre>');
Object.create... looks to be a third parameter to filter.
Set instead (as variable, not as thisArg).