How to use string to store to EEPROM for multiple key (max 6)inputs in an order?

Projects Programming
1

I have a small program and I need it to record the keypress after the void inputScreen(). I made it so it writes the key into string, but how can I make it record all the keys in order, and when there are 6 key-presses to stop reading input and printing on LCD.

#include <glcd.h>
#include <Keypad.h>
#include <fonts/allfonts.h>
#include <EEPROM.h>

int led = 13;
const byte ROWS = 4; //four rows
const byte COLS = 3; //three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'C','0','E'}
};
byte rowPins[ROWS] = {5, 4, 3, 2}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {8, 7, 6}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup(){
  pinMode(led, OUTPUT);
  GLCD.Init();
  GLCD.SelectFont(Arial14);
  welcomeScreen(); //Go to welcome screen and wait for 'C' key only. (I need to disable any other keys until void inputScreen)
}
void inputScreen()
{
  GLCD.ClearScreen();
  GLCD.CursorTo(3, 1);
  GLCD.print("Va     rugam");
  GLCD.CursorTo(2, 2);
  GLCD.print("Introduceti     PIN");
  GLCD.CursorTo(3, 3);         //Here is where the six # characters will be entered.
  digitalWrite(led, HIGH);
}
  
  
void welcomeScreen() //Draw a simple welcome screen.
{
  GLCD.ClearScreen();
  GLCD.CursorTo(0, 0);
  GLCD.print("*********************");
  GLCD.CursorTo(2, 1);
  GLCD.print("Bine   ati   venit!");
  GLCD.CursorTo(0, 3);
  GLCD.print("*********************");
  GLCD.CursorTo(3, 3);
  digitalWrite(led, LOW); //Will attach it to a step motor later.
}

void loop(){
  String pula; //This is where the pin entered has to be stored. (or any other type of memory input)
  char key = keypad.getKey();
   if (key != NO_KEY)
  {
    pula += (key);
    GLCD.print("#"); //How do I make it print this ONLY on void inputScreen?
    if (key == 'C')
      {
        delay(10);
        inputScreen(); //Only on this keypress go to void inputScreen.
      }
    if (key == 'E') //This should work only AFTER the pin was entered. ... ?
      {
      delay(50);
      GLCD.ClearScreen();
      GLCD.CursorTo(3, 1);
      GLCD.print("Va     rugam");
      GLCD.CursorTo(2, 2);
      GLCD.print("ASTEPTATI");
      GLCD.CursorTo(2, 3);
      GLCD.print("#");
      delay(500);
      GLCD.CursorTo(3, 3);
      GLCD.print("#");
      delay(500);
      GLCD.CursorTo(4, 3);
      GLCD.print("#");
      delay(500);
      GLCD.CursorTo(5, 3);
      GLCD.print("#");
      delay(500);
      GLCD.CursorTo(6, 3);
      GLCD.print("#");
      delay(500);
      GLCD.CursorTo(7, 3);
      GLCD.print("#");
      delay(500);
      GLCD.CursorTo(8, 3);
      GLCD.print("#");
      delay(500);
      GLCD.ClearScreen();
      GLCD.CursorTo(5, 1);
      GLCD.print("PIN");
      GLCD.CursorTo(4, 2);
      GLCD.print(pula); //Here I want it to print out the pin that was entered (limited to 6) on the void inputScreen.
      delay(2500);
      welcomeScreen();  //Go back and wait for 'C' key to be pressed to go all over again.
    }
  }
 }
2

I made it so it writes the key into string

Where? I see the code writing to a String. A String and a string are nowhere near the same thing.

but how can I make it record all the keys in order

That seems trivial. Write them as you read them. Writing them in some other order is more challenging.

and when there are 6 key-presses to stop reading input

Count the keys as you read them.