case insensitive array comparison in javascript

Question

I am comparing two arrays for matched items but I need to make them case insensitive.

here is the code: credit for this code to @PatrickRoberts here

const words = ['word1', 'word2', 'word3']
const texts = [
    {name: 'blah', description: 'word4'},
    {name: 'blah2', description: 'word1'},
    {name: 'blah3', description: 'word5'}
]

console.log(
  texts.some(
    ({ description }) => words.includes(description)
  )
)

I was able to get the second part to lower case by doing words.includes(description.toLowerCase()) but I don't know how to handle the first part: texts.some(({ description }) I should mention I have tried adding toLowerCase() to { description } like this: { description.toLowerCase() } but this does not work

any help is greatly appreciated

Ele · Answer 1 · 2019-03-01T23:21:09.157

3

Switch either to the function some or function find or function findIndex.

const words = ['Word1', 'word2', 'word3']
const texts = [{    name: 'blah',    description: 'word4'  },  {    name: 'blah2',    description: 'word1'  },  {    name: 'blah3',    description: 'word5'  }];

console.log(texts.some(({description}) => words.some((w) => w.toLowerCase() === description.toLowerCase())));

edited Mar 01 '19 at 23:21

answered Mar 01 '19 at 23:15

Ele

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I will accept your answer as soon as stackoverflow lets me – Jason Mar 01 '19 at 23:21
Calling `description.toLowerCase()` in the inner arrow function is unnecessarily repeating a large amount of work that could be done in the outer arrow function instead. – Patrick Roberts Mar 01 '19 at 23:42

score 2 · Answer 2 · answered Mar 01 '19 at 23:22

2

No, it's not possible to change it during the destructuring process - this answer explains why.

It's much easier to check by using some instead of includes:

const words = ['word1', 'word2', 'word3']
const texts = [{
    name: 'blah',
    description: 'word4'
  },
  {
    name: 'blah2',
    description: 'word1'
  },
  {
    name: 'blah3',
    description: 'word5'
  }
]

console.log(
  texts.some(
    ({
      description
    }) => words.some(word => word.toLowerCase == description.toLowerCase())
  )
)

answered Mar 01 '19 at 23:22

Jack Bashford

43,180
11
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How is this different than [Ele's answer](https://stackoverflow.com/a/54953587/1541563)? – Patrick Roberts Mar 01 '19 at 23:43
Sorry @PatrickRoberts I didn't realise Ele had posted since I was on mobile. – Jack Bashford Mar 01 '19 at 23:43

molamk · Answer 3 · 2019-03-02T00:14:12.977

0

Use JSON.stringify to convert your objects into strings
Apply .toLowerCase to the obtained strings so that everything (including all values) becomes lowercase
Convert back into an object or array using JSON.parse
Apply the rest of the matching logic with Array.some and Array.includes

const words = ['WORD1', 'WORD2', 'WORD3'];
const texts = [
    {name: 'blah', description: 'word4'},
    {name: 'blah2', description: 'word1'},
    {name: 'blah3', description: 'word5'}
];

const lower = x => JSON.parse(JSON.stringify(x).toLowerCase());
const [lowerWords, lowerTexts] = [words, texts].map(lower);

console.log(
  lowerTexts.some(
    ({ description }) => lowerWords.includes(description)
  )
)

edited Mar 02 '19 at 00:14

answered Mar 01 '19 at 23:21

molamk

4,076
1
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yeah you're right @Ele . Thanks for catching that, I'll put an edit – molamk Mar 01 '19 at 23:23
This assumes that the `description` words are always lowercase as well. That isn't necessarily true. – Patrick Roberts Mar 01 '19 at 23:44
@PatrickRoberts right, `description` may not be lowercase. I'll put an edit. Thanks for catching that – molamk Mar 01 '19 at 23:56

case insensitive array comparison in javascript

3 Answers3