CODEWITHSUNDEEP
javascript
nikotromus
nikotromus

Reputation: 1064

Is there a cleaner way to sort through a list?

I'm working with ES6 and React. I'm parsing through a response object from a Java Rest service, and it dawned on me that there's probably a cleaner way of doing parsing an object into two objects. This wokrs, it just looks clunky.

            let draftList = [];
            let readyForApprovalList = [];
            for (let i = 0; i < action.allStatusesSurveysList.length; i++){
                if (action.allStatusesSurveysList[i].status === statusTypes.DRAFT){
                    draftList.push(action.allStatusesSurveysList[i]);
                } else if (action.allStatusesSurveysList[i].status === statusTypes.READY_FOR_APPROVAL){
                    readyForApprovalList.push(action.allStatusesSurveysList[i]);
                }
            }

Upvotes: 2

Views: 43

Answers (2)

TimoStaudinger
TimoStaudinger

Reputation: 42480

A combination of Array.prototype.filter() and arrow filter functions would be a pretty clean solution.

Note that while this solution is nice and readable, it is not the most efficient one as it takes at least two iterations of the array. However, it may very well be efficient enough for the vast majority of use cases and for this reason a good trade-off.

const draftList = action.allStatusesSurveysList 
    .filter(i => i.status === statusTypes.DRAFT)
const readyForApprovalList = action.allStatusesSurveysList
    .filter(i => i.status === statusTypes.READY_FOR_APPROVAL)

You could even extract the status filter function further:

const byStatus = status => item => item.status === status

const draftList = action.allStatusesSurveysList
    .filter(byStatus(statusTypes.DRAFT))
const readyForApprovalList = action.allStatusesSurveysList
    .filter(byStatus(statusTypes.READY_FOR_APPROVAL))

Upvotes: 2

Niet the Dark Absol
Niet the Dark Absol

Reputation: 324750

forEach would probably work better here - while you can use filter, it would require one pass for each category type.

action.allStatusesSurveysList.forEach(function(item) {
    switch(item.status) {
        case statusTypes.DRAFT:
            draftList.push(item);
            break;
        case statusTypes.READY_FOR_APPROVAL:
            readyForApprovalList.push(item);
            break;
        default:
            // "unknown status" list??
    }
});

This will iterate over the array and has the neat extra of using item instead of repeatedly putting action.allStatusesSurveysList[i]. Also, using a switch statement is better than if..else if..

Upvotes: 1

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