How can I select specific characters in an array without using RegEx in Javascript?

I am doing multiple coding challanges to join a coding bootcamp but have been stuck at the same problem for a few days now.

I have looked online, tried differen solutions, but nothing seems to pass their specific test on their console.

Instructions

Create a function named extractPassword which takes an array of characters (which includes some trash characters) and returns a string with only valid characters (a - z, A - Z, 0 - 9).

Here's an example:

extractPassword(['a', '-', '~', '1', 'a', '/']); // should return the string 'a1a'
extractPassword(['~', 'A', '7', '/', 'C']); // should return the string 'A7C' 

TRY 1:

I first tried using a RegEx:

var newArray = [];

var extractPassword = function(arr){
    //in this area I display the array:
 
    console.log('arr: ' + arr);
    
    //here I transformed the array into a string with the method .join() and then looked for a match with the method .match() with the parameter of a RegExp with a g at the end so it doesn't stop after the first match:
    return arr.join('').match(/[a-zA-Z0-9]/g);
};

console.log(extractPassword(['a','-','~','1','a','/']).toString().replace(/,/g, ''));

The end result is what I wanted: a1a

But the output on their programe gave me an error:
>>>Code is incorrect RegExs are cool, but that is not the type of solution we are looking for.

TRY 2
Then, I tried combining a function with a for loop and an if statement:

var newArray = [];

extractPassword(['a','-', '~', '1', 'a', '/']);

//extractPassword(['~','A','7','/','C']);

function extractPassword(arr){
    //here I console.log the array, to ensure I am passing the right value to the function:
    console.log('arr: ' + arr);
    
    //Here I atribute the array transformed into a string to the var arrayToString:
    var arrayToString = arr.join('');
    
    //Here I console.log the value of the var arrayToString to ensure I am displaying what I want: a string:
    
    console.log('arrayToString: ' + arrayToString);
    
    //Here I will use a for loop to iterate through the characters of the string, and create the var charCode, which will transform each element of the arrayToString var (i) into a Unicode value with the method charCodeAt():
    
    for (var i = 0; i < arrayToString.length; i++){
        var charCode = arrayToString.charCodeAt(i);
        //Here I console.log the different i elements of the arrayToString variable and also its charCode value:
        console.log('charCode ' + i + ':' + charCode);
        
        //Here I will insert a condition to say: 'If we have a character between a and z OR A and Z OR 0 and 9, push those characters into the newArray':
        
        if((charCode > 47 && charCode < 58) || (charCode > 64 && charCode < 91) || (charCode > 96 && charCode < 123)){
            newArray.push(arr[i]);
            console.log('newArray: ' + newArray);
        }
        
    }

    console.log('Final string: ' + newArray.join(''));
}

The result that gives me here is a1a, but the console still gives me an error: >>Code is incorrect. Your function is not returning the correct value.

Does anyone have an alternative way to do what they ask for? I have tried a few other things, but I've been at this for so long, I can's get unstuck.

It looks like you want to use the .filter() method to get rid of any character in the array that isn't within the ranges 0-9, A-Z, and a-z. You can then just call .join() on the resulting array. Like this:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

const extractPassword = arr => arr.filter(ch => (ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z')).join('');

console.log(extractPassword(['a', '-', '~', '1', 'a', '/'])); // should return the string 'a1a'
console.log(extractPassword(['~', 'A', '7', '/', 'C'])); // should return the string 'A7C'

<!-- end snippet -->

Note that you can compare the character with other characters; you don't have to call .charCodeAt() and then compare it with ASCII values.

To do this without Regex, you could create an Array.filter() that leverages String.codePointAt(), and apply that filter to your inputs, which were conveniently provided to you already in array form.

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

const firstCodePoint = 48; // A
const lastCodePoint = 122; // 9

const isAlphaNumeric = (character) => {
  const thisCodePoint = character.codePointAt(0);
  return (thisCodePoint >= firstCodePoint) && (thisCodePoint <= lastCodePoint);
};

const extractPassword = (arr) => {
  const filteredString = arr.filter(isAlphaNumeric).join("");
  return filteredString;
};

console.log( extractPassword(['a', '-', '~', '1', 'a', '/']) ); // 'a1a'
console.log( extractPassword(['~', 'A', '7', '/', 'C']) ); // 'A7C'

<!-- end snippet -->