Performing operations on an array of objects using underscores

Question

Performing operations on an array of objects using underscores

When working with arrays of objects in JavaScript, the Underscore library's functions for array intersection, difference, and union may not work as expected. For example:

var first = {val: 1};
var otherFirst = {val: 1};
var second = {val: 2};
_.difference([first, second], [otherFirst]); // result is [first, second] instead of [second]

This discrepancy occurs because JavaScript compares objects based on reference equality. So how can two arrays of objects be intersected?

I am seeking an idiomatic solution to this issue.

javascript arrays underscore.js

Answer 1

Answer №1

Here's a solution that can handle two arrays:

_.filter([arrayOne, arrayTwo], function(element){
    return !_.findWhere([otherArray], element); 
});

This code essentially checks if an element in the first array is not present in the second array and filters it out.

Answer 2

Here's a solution that can handle two arrays:

_.filter([arrayOne, arrayTwo], function(element){
    return !_.findWhere([otherArray], element); 
});

This code essentially checks if an element in the first array is not present in the second array and filters it out.

Answer 3

Answer №2

To effectively remove elements, one can utilize the remove method:

_.remove([primary, secondary], alternatePrimary)

Answer 4

To effectively remove elements, one can utilize the remove method:

_.remove([primary, secondary], alternatePrimary)

Performing operations on an array of objects using underscores

Answer №1

Answer №2

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