CODEWITHSUNDEEP
javascriptarraysnode.jsecmascript-6
Toko Goshadze
Toko Goshadze

Reputation: 63

JavaScript - Replacing for loop with array helpers

So today I was learning about some ES6 array helpers, and I wanted to change my existing for loops with them, but I can not get same result as i was taking with for loop

function comment(){
    let index;
    for(let i = 0; i < commentArray.length; i++){
        if(commentArray[i]._id == req.params.commentId){
            index = commentArray.indexOf(commentArray[i]);
        }
    }
    return index;
}
var com = comment();

It is nodejs and I am trying to get element index from database, and than pull from it, my code works just fine, but I want to change it with array helper, I guess I need find helper, but I can not make it work!

Upvotes: 0

Views: 103

Answers (2)

Suren Srapyan
Suren Srapyan

Reputation: 68635

If you want to find the index of the item in the array based on some condition, you can use findIndex function

commentArray.findIndex(comment => comment._id === req.params.commentId)

Also with your current code with for loop, I think you need return the index as soon as it is found and not let the loop iterate till the end.

for(let i = 0; i < commentArray.length; i++){
    if(commentArray[i]._id == req.params.commentId){
        return commentArray.indexOf(commentArray[i]);
    }
}

Upvotes: 3

31piy
31piy

Reputation: 23859

You can replace your for loop with this one-liner which uses Array#findIndex:

let index = commentArray.findIndex(comment => comment._id === req.params.commentId);

When this line executes, it will assign the index of comment, which has _id attribute same as req.params.commentId.

Upvotes: 3

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