CODEWITHSUNDEEP
javascript
BARNOWL
BARNOWL

Reputation: 3589

How to search for specific string value thats has corresponding text

I'm trying to check for a value that matches in an array of strings.

So something like this works

const usernames = ['owlman', 'neo', 'trinity'];
const name = 'neo'

if(usernames.indexOf(name) > -1 ){
  console.log('you found me')
}
else{
  console.log('no luck finding user')
}

but what happens if you have a textarea comment, and you want to mention a user with comment data so you do something like this

const usernames = ['owlman', 'neo', 'trinity'];
const name = '@neo you look like the one!'

if(usernames.indexOf(name) > -1 ){
  console.log('you found me')
}
else{
  console.log('no luck finding user') // this gets callee
}

demo

https://jsbin.com/gepiqopiri/edit?js,console

How can i search for a specific value that is an array when there is corresponding data along with it . Is indexOf the approach i want to be using ?

Upvotes: 0

Views: 33

Answers (2)

Prathap Reddy
Prathap Reddy

Reputation: 1739

Check if name includes any user from usernames as below

const usernames = ['owlman', 'neo', 'trinity'];
const name = '@neo you look like the one!';

if(usernames.some(user => name.includes(user))) {
  console.log('you found me'); // this will be called on match
} else {
  console.log('no luck finding user');
}

Upvotes: 1

Matt U
Matt U

Reputation: 5118

indexOf will only find a match for the exact object you pass to it. Your first example works because "neo" does exist as an item in the usernames array. Your second example fails, however, because the array does not contain an entry for "@neo you look like the one".

You'll need to parse your name string and extract a username, then use usernames.indexOf to see if it exists. You can split the name string at spaces and then check for a word that begins with '@', or you can use regex.

Splitting 

var usernames = ['neo', 'other'];
var name = '@neo you look like the one';

// Split the name string at each space
var splitBySpace = name.split(' ');

// Get each item in the split where it begins with @
// The .map uses substring(1) to remove the @ prefix
var atNames = splitBySpace.filter(n => n.indexOf('@') === 0).map(n => n.substring(1));

console.log(atNames[0]);    // neo
console.log(usernames.indexOf(atNames[0]) >= 0);    // true

Regular Expressions

var usernames = ['neo', 'other'];
var name = '@neo you look like the one @other';

// Get each mentioned name with regex
var atNames = [...name.matchAll(/\@[^\s]+/g)];

// Strip @ prefix from each match
var atNamesToMatch = atNames.map(n => n[0].substring(1));

console.log(atNamesToMatch.length);    // 2 ("neo" and "other")
console.log(usernames.indexOf(atNamesToMatch[0]) >= 0);    // true
console.log(usernames.indexOf(atNamesToMatch[1]) >= 0);    // true

Upvotes: 1

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