CODEWITHSUNDEEP
javascriptarraysobjectlodashslice
Geo
Geo

Reputation: 2691

Starting lodash map from index 1

I am currently using lodash map to map over an array of objects.

I always need index 0 in the array to do something different. Is there a way to make map start at index 1, without mutating or messing with the array?

I know that I can use slice(1). Just wondering if there was another way to start from index 1 rather than 0. So I didn't have to join them back together afterwards.

Upvotes: 1

Views: 14154

Answers (1)

Prerak Sola
Prerak Sola

Reputation: 10009

The second parameter of map accepts a function which has 3 arguments (value, index|key, collection). So you can skip the first value using index and play with the rest of your data using value.

Something like this:

let data = [0, 1, 2];

let result = _.map(data, (value, index) => {
  if (index === 0) {
    return value;
  } else {
    return value * 2;
  }
});

console.log(result);
<script src="https://cdn.jsdelivr.net/npm/[email protected]/lodash.min.js"></script>

Upvotes: 9

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