A condition inside another condition in function not working

Second question after making changes

Ok. I've changed a few things to reduce confusion and added alert for invalid user input. The code still is not working and not quite sure why.

function generatePassword() {



var uppercaseArray = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"];
var lowercaseArray = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o",  "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"];
var numbArray = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"];
var characterArray = ["@", "#", "$", "%", "^", "&", "*", "(", ")", "-", "_", "=", "+"];



var resultArray = [];
var userArray = [];

uppercaseArray [1]
//-----------------------------------------------------------------
  var numCharacter = prompt ("How many number of Characters do you want in your password? (You can pick between 8 and 128)");
  var numbers = confirm ("you want numbers in your password?");
  var uppercases = confirm ("you want Uppercases in your password?");
  var lowercases = confirm ("you want lowercases in your password?");
  var characters = confirm ("you want special characters in your password?");




  if(numCharacter < 8 || numCharacter > 128) {

     if (numbers){
      resultArray = resultArray.concat(numbArray);

    }

     if (uppercases){
      resultArray = resultArray.concat(uppercaseArray);

    }

     if (lowercases){
      resultArray = resultArray.concat(lowercaseArray);

    }

     if (characters){
      resultArray = resultArray.concat(characterArray);
    }
    console.log(resultArray)


    for (var i = 0; i < numCharacter; i++) {

      userArray.push (resultArray[Math.floor(Math.random() * resultArray.length)]); 
      }



      return userArray.join("") ;


}

}else{

alert("Please pick numbers between 8 and 128.");
}

---

Initial question

I'm trying to give a prompt window to the users when 'generate password' button is clicked then if the user input is invalid (not between 8 to 128) I want to pop alert window saying 'Please pick between 8 and 128'. When I add if (numCharacter => "8" || numCharacter => "128") function stops working for some reason. Could anyone tell me what went wrong?