Javascript for loop to filter conversion

Question

I have following script which filter the data using for loop as shown

let i;
const filteredFriends = [];

for (i = 0; i < users.length; i += 1) {
  if (this.isUserExist(users[i]) {
    filteredFriends.push(users[i]);
  }
}

How can i covert it into filter

any idea please

@MunishKapoor So you *did* try something, but it didn't work. We'd appreciate if you posted your failed attempts so we can help you understand what you did wrong. — Barmar, Aug 11 '20 at 15:42

score 2 · Accepted Answer · answered Aug 11 '20 at 15:39

Simply use the if condition in the callback function of filter(). Replace user[i] with the callback function parameter.

const filteredFriends = users.filter(u => this.isUserExist(u))

Make sure you use an arrow function so that this will be inherited in the callback function. If you need compatibility with older implementations that don't have arrow functions, see How to access the correct `this` inside a callback?

score 0 · Answer 2 · answered Aug 11 '20 at 15:39

0

let filteredFriends = users.filter(user => {
    return this.isUserExist(user);
});

answered Aug 11 '20 at 15:39

Sascha

4,576
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Please don't post code without a textual explanation. – bad_coder Aug 12 '20 at 03:23

score 0 · Answer 3 · answered Aug 11 '20 at 15:40

0

Simply do this:

const users = ['spray', 'limit', 'elite', 'exuberant', 'destruction', 'present'];
let filteredFriends = users.filter(user => this.isUserExist(user));
console.log(filteredFriends);

answered Aug 11 '20 at 15:40

Jawad

190
10

score 0 · Answer 4 · answered Aug 11 '20 at 16:18

0

filter method need to return boolean value. your function this.isUserExist seems doing that as you have used in if condition.

Use it like.

const filteredFriends = users.filter(this.isUserExist);

answered Aug 11 '20 at 16:18

Siva K V

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2
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Javascript for loop to filter conversion

4 Answers4