CODEWITHSUNDEEP
javascriptlodash
Maxim Mig
Maxim Mig

Reputation: 1

Lodash lazy chain doesn't work for me

What I expect from this code is [1, 2, 5, 6, 7, 8, 9]. The result is [7, 8, 9]. Where is my mistake? Jsfiddle for this. Thanks.

var ar = [1, 2, 3, 4, 5, 6],
    arWrapper = _(ar),
    removedTypes = [3, 4],
    addedTypes = [7, 8, 9];

_.each(removedTypes, function (removedType) {    
    arWrapper = arWrapper.remove(function (type) {
        return type === removedType;
    });
});
_.each(addedTypes, function (addedType) {
    arWrapper = arWrapper.push(addedType);
});

console.log("%O", arWrapper.value());

Upvotes: 0

Views: 302

Answers (1)

zerkms
zerkms

Reputation: 254926

Your solution is not "idiomatic", since it relies on free variables here and there (and is "too imperative" overall):

The "better" solution would be:

var result = arWrapper.difference(removedTypes).union(addedTypes);

JSFiddle: http://jsfiddle.net/xb90agw2/1/

As of your solution - it does not work because .remove() returns a collection of removed elements, not the collection with filtered out elements as you assume.

Upvotes: 2

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