Mockup1Demo/Assets/NPCDialogue.cs

using System.Collections;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

public class NPCDialogue : MonoBehaviour
{
        public GameObject dialoguePanel;
    public TextMeshProUGUI dialogueText;
    public string[] dialogue;
    private int index;

    public GameObject contButton;

    public float wordSpeed;
    public bool playerIsClose;

    bool isTyping = false;
    // Update is called once per frame
    void Update()
    {
        if(Input.GetKeyDown(KeyCode.E) && playerIsClose && isTyping == false) {
            if (dialoguePanel.activeInHierarchy) {
                // zeroText();
                NextLine();
            } else {
                dialoguePanel.SetActive(true);
                contButton.SetActive(false);
                StartCoroutine(Typing());
            }
        }

        if(dialogueText.text == dialogue[index]) {
            contButton.SetActive(true);
            isTyping = false;
        }
    }

    public void zeroText() {
        dialogueText.text = "";
        index = 0;
        isTyping = false;
        dialoguePanel.SetActive(false);
    }

    IEnumerator Typing() {
        foreach(char letter in dialogue[index].ToCharArray()) {
            dialogueText.text += letter;
            yield return new WaitForSeconds(wordSpeed);
        }
    }

    public void NextLine () {
        contButton.SetActive(false);
        if (index < dialogue.Length - 1) {
            index++;
            dialogueText.text = "";
            isTyping = true;
            StartCoroutine(Typing());
        } else {
            zeroText();
        }
    }

    private void OnTriggerEnter2D(Collider2D other) {
        if (other.CompareTag("Player")) {
            playerIsClose = true;
        }
    }

    private void OnTriggerExit2D(Collider2D other) {
        if (other.CompareTag("Player")) {
            playerIsClose = false;
            zeroText();
        }
    }

}