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javascriptlodash

Why does this lodash includes return true?

I have a csv value and need to check that one of the csv values in my array units available.

Why do I get in both cases true?

let arr = [16]
let check = _.includes('14,15,16,17,18,19', arr)
console.log(check);

arr = [6]
check = _.includes('14,15,16,17,18,19', arr)
console.log(check);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js"></script>

Solution

  • The signature of _includes is

    _.includes(collection, value, [fromIndex=0])

    And in case the collection is a string - which it is here:

    If collection is a string, it's checked for a substring of value

    And both values you're passing - [16] and [6] - when coerced to strings - exist as substrings. ('16' and '6')

    It sounds like you might want to turn the string into an array of numbers first - and check against only a single value, not an array. Eg:

    const inputString = '14,15,16,17,18,19';
const arrOfNumbers = JSON.parse(`[${inputString}]`);
console.log(arrOfNumbers.includes(16));
console.log(arrOfNumbers.includes(6));