How to remove/delete Button text on when check button is clicked?

Question

I am making this sum creator where user will have to type an answer using custom keyboard. and on check button click if answer is correct then new question is loaded.

My problem is after answering first question answer button reset to blank but when user types next answer, only one last alphabet is deleted (for example 5 from 15). and when i type 14 it shows 114 (1 from previously typed answer).

I need help to reset answer button text to blank.

I am using buttons because later i want to add more questions at the same time so user will have multiple answers to click and type.

Can anyone please help me on this? Also tell me if this is the right method to achieve what i want.

I am calling backspace function to delete previous answer and also setting text to blank.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Keyboard : MonoBehaviour
{
    string word = null;
    int wordIndex = -1;
    string alpha = null;
    string alpha2 = null;
    public Text userAnswer1 = null;
    public Text valueA, valueB;
    public Text scoreCount;
    private int a, b, answer1, score;
    char[] nameChar = new char[5];


    private void Start()
    {          
        SumCreator();
    }

    public void nameFunc (string alphabet)
    {
        wordIndex++;
        char[] keepchar = alphabet.ToCharArray();
        nameChar[wordIndex] = keepchar[0];
        alpha = nameChar[wordIndex].ToString();
        word = word + alpha;
        userAnswer1.text = word;      
    }

    public void BackspaceFunction()
    {
        if (wordIndex >= 0)
        {
            wordIndex--;

            alpha2 = null;
            for (int i = 0; i < wordIndex + 1; i++)
            {
                alpha2 = alpha2 + nameChar[i].ToString();
            }
            word = alpha2;
            userAnswer1.text = word;
        }
    }

    public void SumCreator ()
    {
        a = Random.Range(0,15);
        b = Random.Range(0,15);
        answer1 = a + b;
        valueA.text = a.ToString();
        valueB.text = b.ToString();
        scoreCount.text = "score " + score.ToString();
    }

    public void CheckAnswer()
    {
        Text buttonText = userAnswer1.GetComponentInChildren<Text>();

        if (answer1 == int.Parse(userAnswer1.text))
        {
            score++;
            // userAnswer1.text = string.Empty;
            buttonText.text = string.Empty;
        }  

        SumCreator();
    }
}

Answer 1

I've edited my answer and removed the now irrelevant parts.

Once the button "Check" is clicked, first of all erase the text in the result textbox, then do the whole other logic. To erase the text you can use next piece of code:

Text buttonText = buttonName.GetComponentInChildren<Text>();
buttonText.text = string.Empty;

You probably want to have this "buttonText" property as a global and get it once, at the start of the program instead of getting it every time the button is clicked. It won't do much difference in a small scale program, but it's a right way of thinking.

After checking your code a bit more, I can summarize your problem:

The whole logic of your program is flawed, there're many unnecessary complicated things which make it fail in several places. It is understandable, everybody goes through this stage, nothing to be ashamed or worried about. Either way it's my subjective opinion, which may be wrong.

Back to your code, all you have to do is update your result text, say "txtResult", once anything happens.

Once you click a number, do "txtResult += numberClicked".

Once you click backspace, remove last char of txtResult. Here is a question with many answers on how to do it, it's really simple.

Once you click "Check", in case it's the right number, set txtResult to empty.

Also, every time you update txtResult, you're supposed to update the UI too of course. Let's say you do it every time, it would be one line to update txtResult, and one line to update UI for each of the above 3 cases. So in total 6 lines. A check for an empty string while in "Backspace" function adds another line. My math could be wrong, but either way, it's quite short and simple approach, nothing too complicated.

You just lack relevant knowledge, otherwise you wouldn't be doing that nightmare in your Backspace function.

Regarding the "nameFunc" function, the whole 6 lines could be replaced with "txtResult += alphabet", isn't it? I'm not sure what you get in alphabet parameter, but either way, string is an array of chars, so you can also do "txtResult += alphabet[0]" instead of what you have there.

So, in total, you got it all right, the logic was right, you figured the main aspects. But you over complicated the whole thing. I believe you'll be fine after reading all this text, and wish you the best.

Answer 2

If you want to clear your Text object when you have succesfully entered your answer, you should not call your "BackSpace" function.

Just replace your code to this:

if (answer1 == int.Parse(userAnswer1.text))
{
    score++;
    userAnswer1.text = string.Empty;

This will clear the text element.

You could also look into using InputFields in Unity, which are designed for entering input and automatically support backspace and other keyboard functions. If you do, make sure that you set the InputField's ContentType to either Integer Number or Decimal Number