I have two arrays:
array a:
var a = [
{
id: 1,
name: 'a'
},
{
id: 2,
name: 'b'
},
{
id: 3,
name: 'c'
}
];
array ids:
var ids = [1];
I want to array a filtered by array ids, result i wanted:
var a = [
{
id: 1,
name: 'a'
}
];
The most important thing is i want the change on the original array, rather than return a new array.
underscore solution is better:)
You can use .filter
a = a.filter(function(el){
return ~ids.indexOf(el.id)
});
// should give you [{id: 1, name: 'a'}]
Today I tried to solve similar task (filtering the original array of objects without creating a new array) and this is what I came up with:
const a = [{ id: 1, name: 'a'}, { id: 2, name: 'b'}, { id: 3, name: 'c'}];
const ids = [1];
Array.from(Array(a.length).keys()).reverse().forEach(index =>
!ids.some(id => id === a[index].id) && a.splice(index, 1)
);
console.log(a); // [{ id: 1, name: 'a'}]
The point is that we need to loop back through the original array to be able to use Array.prototype.splice, but I didn't want the for-loop, I wanted to have ES6 one-liner. And Array.from(Array(a.length).keys()).reverse() gives me a list of reversed indexes of the original array. Then I want to splice the original array by current index only if the corresponding item's id is not present in the ids array.