JavaScript to check if string has at least three characters that are in another variable

Question

I have a variable activeUserName and a variable manager1.

How can I check if activeUserName contains at least three characters, that are in manager1? (The position of those characters doesn't matter)

For example in the following case, it should return true, because the characters 'J', 'o' and 'e' are inside manager1.

var activeUserName = "JohnDoe100";
var manager1 = "JYZALoe999";

Right now I'm using the indexOf method and only look at characters in certain positions which is why I want to change that:

if (isEditor == false){
    if (((activeUserName.indexOf(manager1.charAt(0)) !== -1)  && (activeUserName.indexOf(manager1.charAt(2)) !== -1)) || (activeUserName.indexOf(manager1.charAt(4)) !== -1)){
        // doSth();
    } else if (((activeUserName.indexOf(manager2.charAt(0)) !== -1)  && (activeUserName.indexOf(manager2.charAt(2)) !== -1)) || (activeUserName.indexOf(manager2.charAt(4)) !== -1)){
        // doSth();
    } else {
        // doSth();
    }
}

I read about Regex, but I'm not sure if this can be applied here.

Any help is appreciated!

Answer 1

Combining .split() with .filter() you can trasform activeUserName in array and filter each char against the string manager1:

var activeUserName = "JohnDoe100";
var manager1 = "JYZALoe999";

var howMany = activeUserName.split('').filter(function(e, i, a) {
    return (manager1.indexOf(e) != -1);
}).length;

console.log('The number of chars in common is: ' + howMany);

Answer 2

var activeUserName = "JohnDoe100";
    var manager1 = "JYZALoe999";
    const arr1 = [...activeUserName];
    const arr2 = [...manager1];
    let count = 0;
    for (let i = 0; i<arr1.length; i++) {
      if (arr2.indexOf(arr1[i]) !== -1) count++;
    }
if(count >= 3)
  console.log(`string b 3 same values of string b`);

Answer 3

Use For loop with break and Use includes()

To be clean, make a function that will do the job.

To be efficent use break when you find 3 match chars.

Prefer not to use var, use const and let.

const areStringsMatchCharsMoreThen2 = (stringA, stringB) => {
  let count = 0;
  for (let i = 0; i < stringB.length; i++) {
    if (count === 3) break;
    if (stringA.includes(stringB.charAt(i))) count++;
  }
  return count === 3;
}

const activeUser = "JohnDoe100";
const manager = "JYZALoe999";

const areStringsMatchCharsMoreThen2 = (stringA, stringB) => {
  let count = 0;
  for (let i = 0; i < stringB.length; i++) {
    if (count === 3) break;
    if (stringA.includes(stringB.charAt(i))) count++;
  }
  return count === 3;
}

console.log(areStringsMatchCharsMoreThen2(activeUser, manager));
console.log(areStringsMatchCharsMoreThen2('ABC', 'def'));