From 55c43d3ba2394c68d766525bbace3e923e514db5 Mon Sep 17 00:00:00 2001
From: tuhindas56 <67787961+tuhindas56@users.noreply.github.com>
Date: Tue, 12 Mar 2024 11:21:14 +0530
Subject: [PATCH] Revert "Dump old code"

This reverts commit 12a1b2af6af6896986bcb09dfedfc943d3e11b96.
---
 dist/app.js | 413 +++++++++++++++++++++++++++++++++++++++++++++++
 src/app.ts  | 452 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 865 insertions(+)

diff --git a/dist/app.js b/dist/app.js
index 3918c74..86a528d 100644
--- a/dist/app.js
+++ b/dist/app.js
@@ -1 +1,414 @@
 "use strict";
+const expressionDisplay = document.querySelector("#expression");
+const resultDisplay = document.querySelector("#result");
+const buttons = document.querySelector("#button-container");
+const MAX_INPUT_LENGTH = 13;
+const MAX_RESULT_LENGTH = 14;
+let calculator = {
+    firstOperand: "",
+    operator: "",
+    secondOperand: "",
+    result: "",
+};
+buttons.addEventListener("click", (event) => {
+    const target = event.target;
+    switch (target.id) {
+        case "btn-zero":
+            inputBtnClicked("0");
+            break;
+        case "btn-one":
+            inputBtnClicked("1");
+            break;
+        case "btn-two":
+            inputBtnClicked("2");
+            break;
+        case "btn-three":
+            inputBtnClicked("3");
+            break;
+        case "btn-four":
+            inputBtnClicked("4");
+            break;
+        case "btn-five":
+            inputBtnClicked("5");
+            break;
+        case "btn-six":
+            inputBtnClicked("6");
+            break;
+        case "btn-seven":
+            inputBtnClicked("7");
+            break;
+        case "btn-eight":
+            inputBtnClicked("8");
+            break;
+        case "btn-nine":
+            inputBtnClicked("9");
+            break;
+        case "btn-dot":
+            inputBtnClicked(".");
+    }
+    switch (target.id) {
+        case "btn-add":
+            handleOperatorClick("+");
+            break;
+        case "btn-subtract":
+            handleOperatorClick("-");
+            break;
+        case "btn-multiply":
+            handleOperatorClick("*");
+            break;
+        case "btn-divide":
+            handleOperatorClick("/");
+            console.log(calculator.firstOperand);
+            console.log(calculator.secondOperand);
+            break;
+        case "btn-percentage":
+            percentageBtnClicked();
+            break;
+        case "btn-equals":
+            equalsBtnClicked();
+            break;
+    }
+    switch (target.id) {
+        case "btn-clear":
+            clearButtonClicked();
+            break;
+        case "btn-delete":
+            deleteButtonClicked();
+            break;
+    }
+});
+function inputBtnClicked(input) {
+    const errorMessages = [
+        "Hello!",
+        "Error: Enter a number first!",
+        "Error: Length exceeded!",
+        "Error: No operator chosen!",
+        "Error: Invalid divisor!",
+        "Error: Enter a pair of numbers first!",
+        "Error: Cannot calculate!",
+        "Error!",
+        "Cleared!",
+        "Purged!",
+    ];
+    if (errorMessages.includes(resultDisplay.textContent) || errorMessages.includes(expressionDisplay.textContent)) {
+        return;
+    }
+    if (calculator.result !== "" && expressionDisplay.textContent !== "" && resultDisplay.textContent !== "") {
+        calculator.result = "";
+        expressionDisplay.textContent = "";
+        resultDisplay.textContent = "";
+    }
+    if (calculator.operator == "") {
+        if (calculator.firstOperand.length == MAX_INPUT_LENGTH) {
+            handleError("InputLengthExceeded");
+            calculator.firstOperand = "";
+            return;
+        }
+        if (input === "." && calculator.firstOperand.includes(".")) {
+            return;
+        }
+        calculator.firstOperand += input;
+        resultDisplay.append(input);
+        if (calculator.firstOperand.length > 9) {
+            changeFontSize("change");
+        }
+    }
+    else {
+        if (calculator.secondOperand.length == MAX_INPUT_LENGTH) {
+            handleError("InputLengthExceeded");
+            calculator.secondOperand = "";
+            return;
+        }
+        if (input === "." && calculator.secondOperand.includes(".")) {
+            return;
+        }
+        calculator.secondOperand += input;
+        resultDisplay.append(input);
+    }
+}
+function handleOperatorClick(operator) {
+    if (calculator.firstOperand !== "" &&
+        calculator.secondOperand == "" &&
+        calculator.result == "" &&
+        calculator.operator == "") {
+        calculator.operator = operator;
+        logExpression(operator);
+    }
+    else if (calculator.firstOperand == "" &&
+        calculator.secondOperand == "" &&
+        calculator.result !== "" &&
+        calculator.operator == "") {
+        calculator.firstOperand = calculator.result;
+        calculator.result = "";
+        calculator.operator = operator;
+        expressionDisplay.textContent = "";
+        logExpression(operator);
+    }
+    else if (calculator.firstOperand == "" && calculator.secondOperand == "" && calculator.result == "") {
+        handleError("NoInputOperation");
+    }
+    else {
+        performOperation();
+        calculator.firstOperand = calculator.result;
+        calculator.result = "";
+        calculator.operator = operator;
+        logExpression(operator);
+    }
+}
+function percentageBtnClicked() {
+    if (calculator.firstOperand !== "" && calculator.secondOperand == "" && calculator.result == "") {
+        calculator.firstOperand = `${percentage(calculator.firstOperand)}`;
+        resultDisplay.textContent = calculator.firstOperand;
+    }
+    else if (calculator.firstOperand == "" && calculator.secondOperand == "" && calculator.result == "") {
+        handleError("NoInputOperation");
+    }
+    else if (calculator.firstOperand !== "" && calculator.secondOperand !== "" && calculator.result == "") {
+        calculator.secondOperand = `${percentage(calculator.secondOperand)}`;
+        resultDisplay.textContent = calculator.secondOperand;
+    }
+    else {
+        calculator.firstOperand = calculator.result;
+        calculator.result = "";
+        calculator.firstOperand = `${percentage(calculator.firstOperand)}`;
+        expressionDisplay.textContent = "";
+        resultDisplay.textContent = calculator.firstOperand;
+    }
+}
+function equalsBtnClicked() {
+    if (calculator.firstOperand == "" &&
+        calculator.secondOperand == "" &&
+        calculator.operator == "" &&
+        calculator.result == "") {
+        return handleError("EmptyCalculatorObject");
+    }
+    else if (calculator.firstOperand !== "" &&
+        calculator.secondOperand == "" &&
+        calculator.operator == "" &&
+        calculator.result == "") {
+        calculator.firstOperand = "";
+        return handleError("NoOperatorChosen");
+    }
+    else {
+        performOperation();
+        logExpression("=");
+        if (calculator.result == "undefined" || calculator.result == "NaN") {
+            calculator.result = "";
+            return;
+        }
+        else {
+            resultDisplay.textContent = calculator.result;
+        }
+    }
+}
+function clearButtonClicked() {
+    if (calculator.operator == "") {
+        calculator.firstOperand = "";
+    }
+    else {
+        calculator.secondOperand = "";
+    }
+    if (calculator.firstOperand == "" && calculator.secondOperand == "" && calculator.result !== "") {
+        expressionDisplay.textContent = "";
+        calculator.result = "";
+    }
+    changeFontSize("reset");
+    resultDisplay.textContent = "Cleared!";
+    setTimeout(() => (resultDisplay.textContent = ""), 600);
+}
+function deleteButtonClicked() {
+    calculator = {
+        firstOperand: "",
+        operator: "",
+        secondOperand: "",
+        result: "",
+    };
+    changeFontSize("reset");
+    expressionDisplay.textContent = "";
+    resultDisplay.textContent = "Purged!";
+    setTimeout(() => (resultDisplay.textContent = ""), 600);
+}
+function add(a, b) {
+    return parseFloat((+a + +b).toFixed(10));
+}
+function subtract(a, b) {
+    return parseFloat((+a - +b).toFixed(10));
+}
+function multiply(a, b) {
+    return parseFloat((+a * +b).toFixed(10));
+}
+function divide(a, b) {
+    if (b == "" || b == 0 || b == "0" || b == ".") {
+        handleError("InvalidDivisor");
+        return;
+    }
+    return parseFloat((+a / +b).toFixed(10));
+}
+function percentage(a) {
+    return +a / 100;
+}
+function performOperation() {
+    switch (calculator.operator) {
+        case "+":
+            calculator.result = `${add(calculator.firstOperand, calculator.secondOperand)}`;
+            calculator.firstOperand = "";
+            calculator.secondOperand = "";
+            calculator.operator = "";
+            break;
+        case "-":
+            calculator.result = `${subtract(calculator.firstOperand, calculator.secondOperand)}`;
+            calculator.firstOperand = "";
+            calculator.secondOperand = "";
+            calculator.operator = "";
+            break;
+        case "*":
+            calculator.result = `${multiply(calculator.firstOperand, calculator.secondOperand)}`;
+            calculator.firstOperand = "";
+            calculator.secondOperand = "";
+            calculator.operator = "";
+            break;
+        case "/":
+            calculator.result = `${divide(calculator.firstOperand, calculator.secondOperand)}`;
+            calculator.firstOperand = "";
+            calculator.secondOperand = "";
+            calculator.operator = "";
+            break;
+    }
+    if (calculator.result.length > 9) {
+        changeFontSize("change");
+    }
+    if (calculator.result.length > MAX_RESULT_LENGTH) {
+        handleError("ResultLengthExceeded");
+    }
+}
+function handleError(error) {
+    switch (error) {
+        case "NoInputOperation":
+            displayError("Error: Enter a number first!");
+            break;
+        case "InputLengthExceeded":
+            displayError("Error: Length exceeded!");
+            break;
+        case "NoOperatorChosen":
+            displayError("Error: No operator chosen!");
+            break;
+        case "InvalidDivisor":
+            displayError("Error: Invalid divisor!");
+            break;
+        case "EmptyCalculatorObject":
+            displayError("Error: Enter a pair of numbers first!");
+            break;
+        case "ResultLengthExceeded":
+            displayError("Error: Cannot calculate!");
+            break;
+        default:
+            displayError("Error!");
+            break;
+    }
+}
+function displayError(string) {
+    expressionDisplay.textContent = "";
+    changeFontSize("change");
+    resultDisplay.textContent = string;
+    setTimeout(() => {
+        resultDisplay.textContent = "";
+        expressionDisplay.textContent = "";
+        changeFontSize("reset");
+    }, 700);
+}
+function logExpression(operator) {
+    if (operator == "=") {
+        if (calculator.result == "undefined" || calculator.result == "NaN") {
+            return;
+        }
+        else {
+            expressionDisplay.append(`${resultDisplay.textContent}`);
+            return;
+        }
+    }
+    expressionDisplay.append(`${resultDisplay.textContent}${operator}`);
+    resultDisplay.textContent = "";
+}
+function changeFontSize(string) {
+    if (string == "change") {
+        resultDisplay.style.fontSize = "30px";
+        return;
+    }
+    else {
+        resultDisplay.style.fontSize = "";
+    }
+}
+document.addEventListener("contextmenu", (e) => e.preventDefault());
+window.addEventListener("load", () => {
+    resultDisplay.textContent = "Hello!";
+    setTimeout(() => (resultDisplay.textContent = ""), 700);
+});
+document.addEventListener("keydown", (event) => {
+    if (event.key === "Enter") {
+        event.preventDefault();
+    }
+    switch (event.key) {
+        case "0":
+            inputBtnClicked("0");
+            break;
+        case "1":
+            inputBtnClicked("1");
+            break;
+        case "2":
+            inputBtnClicked("2");
+            break;
+        case "3":
+            inputBtnClicked("3");
+            break;
+        case "4":
+            inputBtnClicked("4");
+            break;
+        case "5":
+            inputBtnClicked("5");
+            break;
+        case "6":
+            inputBtnClicked("6");
+            break;
+        case "7":
+            inputBtnClicked("7");
+            break;
+        case "8":
+            inputBtnClicked("8");
+            break;
+        case "9":
+            inputBtnClicked("9");
+            break;
+        case ".":
+            inputBtnClicked(".");
+    }
+    switch (event.key) {
+        case "+":
+            handleOperatorClick("+");
+            break;
+        case "-":
+            handleOperatorClick("-");
+            break;
+        case "*":
+            handleOperatorClick("*");
+            break;
+        case "/":
+            handleOperatorClick("/");
+            break;
+        case "%":
+            percentageBtnClicked();
+            break;
+        case "=":
+        case "Enter":
+            equalsBtnClicked();
+            break;
+    }
+    switch (event.key) {
+        case "Backspace":
+        case "Escape":
+            clearButtonClicked();
+            break;
+        case "Delete":
+            deleteButtonClicked();
+            break;
+    }
+});
diff --git a/src/app.ts b/src/app.ts
index e69de29..5edfa8c 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -0,0 +1,452 @@
+const expressionDisplay = document.querySelector("#expression") as HTMLElement;
+const resultDisplay = document.querySelector("#result") as HTMLElement;
+const buttons: HTMLElement = document.querySelector("#button-container") as HTMLElement;
+const MAX_INPUT_LENGTH = 13;
+const MAX_RESULT_LENGTH = 14;
+let calculator = {
+  firstOperand: "",
+  operator: "",
+  secondOperand: "",
+  result: "",
+};
+// Handle button clicks
+buttons.addEventListener("click", (event) => {
+  const target = event.target as HTMLElement;
+
+  // Handle input buttons
+  switch (target.id) {
+    case "btn-zero":
+      inputBtnClicked("0");
+      break;
+    case "btn-one":
+      inputBtnClicked("1");
+      break;
+    case "btn-two":
+      inputBtnClicked("2");
+      break;
+    case "btn-three":
+      inputBtnClicked("3");
+      break;
+    case "btn-four":
+      inputBtnClicked("4");
+      break;
+    case "btn-five":
+      inputBtnClicked("5");
+      break;
+    case "btn-six":
+      inputBtnClicked("6");
+      break;
+    case "btn-seven":
+      inputBtnClicked("7");
+      break;
+    case "btn-eight":
+      inputBtnClicked("8");
+      break;
+    case "btn-nine":
+      inputBtnClicked("9");
+      break;
+    case "btn-dot":
+      inputBtnClicked(".");
+  }
+
+  // Handle Operation buttons
+  switch (target.id) {
+    case "btn-add":
+      handleOperatorClick("+");
+      break;
+    case "btn-subtract":
+      handleOperatorClick("-");
+      break;
+    case "btn-multiply":
+      handleOperatorClick("*");
+      break;
+    case "btn-divide":
+      handleOperatorClick("/");
+      console.log(calculator.firstOperand);
+      console.log(calculator.secondOperand);
+      break;
+    case "btn-percentage":
+      percentageBtnClicked();
+      break;
+    case "btn-equals":
+      equalsBtnClicked();
+      break;
+  }
+
+  // Handle other buttons
+  switch (target.id) {
+    case "btn-clear":
+      clearButtonClicked();
+      break;
+    case "btn-delete":
+      deleteButtonClicked();
+      break;
+  }
+});
+
+// Functions called on button clicks
+function inputBtnClicked(input: string) {
+  // Deny input while error messages are displayed
+  const errorMessages = [
+    "Hello!",
+    "Error: Enter a number first!",
+    "Error: Length exceeded!",
+    "Error: No operator chosen!",
+    "Error: Invalid divisor!",
+    "Error: Enter a pair of numbers first!",
+    "Error: Cannot calculate!",
+    "Error!",
+    "Cleared!",
+    "Purged!",
+  ];
+
+  if (errorMessages.includes(resultDisplay.textContent!) || errorMessages.includes(expressionDisplay.textContent!)) {
+    return;
+  }
+  // Reset calculator if no operators are pressed after previous result calculation
+  if (calculator.result !== "" && expressionDisplay.textContent !== "" && resultDisplay.textContent !== "") {
+    calculator.result = "";
+    expressionDisplay.textContent = "";
+    resultDisplay.textContent = "";
+  }
+
+  if (calculator.operator == "") {
+    if (calculator.firstOperand.length == MAX_INPUT_LENGTH) {
+      handleError("InputLengthExceeded");
+      calculator.firstOperand = "";
+      return;
+    }
+
+    if (input === "." && calculator.firstOperand.includes(".")) {
+      return;
+    }
+    calculator.firstOperand += input;
+    resultDisplay.append(input);
+
+    if (calculator.firstOperand.length > 9) {
+      changeFontSize("change");
+    }
+  } else {
+    if (calculator.secondOperand.length == MAX_INPUT_LENGTH) {
+      handleError("InputLengthExceeded");
+      calculator.secondOperand = "";
+      return;
+    }
+    if (input === "." && calculator.secondOperand.includes(".")) {
+      return;
+    }
+    calculator.secondOperand += input;
+
+    resultDisplay.append(input);
+  }
+}
+
+function handleOperatorClick(operator: string) {
+  if (
+    calculator.firstOperand !== "" &&
+    calculator.secondOperand == "" &&
+    calculator.result == "" &&
+    calculator.operator == ""
+  ) {
+    calculator.operator = operator;
+    logExpression(operator);
+  } else if (
+    calculator.firstOperand == "" &&
+    calculator.secondOperand == "" &&
+    calculator.result !== "" &&
+    calculator.operator == ""
+  ) {
+    calculator.firstOperand = calculator.result;
+    calculator.result = "";
+    calculator.operator = operator;
+    expressionDisplay.textContent = "";
+    logExpression(operator);
+  } else if (calculator.firstOperand == "" && calculator.secondOperand == "" && calculator.result == "") {
+    handleError("NoInputOperation");
+  } else {
+    performOperation();
+    calculator.firstOperand = calculator.result;
+    calculator.result = "";
+    calculator.operator = operator;
+    logExpression(operator);
+  }
+}
+
+function percentageBtnClicked() {
+  if (calculator.firstOperand !== "" && calculator.secondOperand == "" && calculator.result == "") {
+    calculator.firstOperand = `${percentage(calculator.firstOperand)}`;
+    resultDisplay.textContent = calculator.firstOperand;
+  } else if (calculator.firstOperand == "" && calculator.secondOperand == "" && calculator.result == "") {
+    handleError("NoInputOperation");
+  } else if (calculator.firstOperand !== "" && calculator.secondOperand !== "" && calculator.result == "") {
+    calculator.secondOperand = `${percentage(calculator.secondOperand)}`;
+    resultDisplay.textContent = calculator.secondOperand;
+  } else {
+    calculator.firstOperand = calculator.result;
+    calculator.result = "";
+    calculator.firstOperand = `${percentage(calculator.firstOperand)}`;
+    expressionDisplay.textContent = "";
+    resultDisplay.textContent = calculator.firstOperand;
+  }
+}
+
+function equalsBtnClicked() {
+  if (
+    calculator.firstOperand == "" &&
+    calculator.secondOperand == "" &&
+    calculator.operator == "" &&
+    calculator.result == ""
+  ) {
+    return handleError("EmptyCalculatorObject");
+  } else if (
+    calculator.firstOperand !== "" &&
+    calculator.secondOperand == "" &&
+    calculator.operator == "" &&
+    calculator.result == ""
+  ) {
+    calculator.firstOperand = "";
+    return handleError("NoOperatorChosen");
+  } else {
+    performOperation();
+    logExpression("=");
+    if (calculator.result == "undefined" || calculator.result == "NaN") {
+      calculator.result = "";
+      return;
+    } else {
+      resultDisplay.textContent = calculator.result;
+    }
+  }
+}
+
+function clearButtonClicked() {
+  if (calculator.operator == "") {
+    calculator.firstOperand = "";
+  } else {
+    calculator.secondOperand = "";
+  }
+  if (calculator.firstOperand == "" && calculator.secondOperand == "" && calculator.result !== "") {
+    expressionDisplay.textContent = "";
+    calculator.result = "";
+  }
+  changeFontSize("reset");
+  resultDisplay.textContent = "Cleared!";
+  setTimeout(() => (resultDisplay.textContent = ""), 600);
+}
+
+function deleteButtonClicked() {
+  calculator = {
+    firstOperand: "",
+    operator: "",
+    secondOperand: "",
+    result: "",
+  };
+  changeFontSize("reset");
+  expressionDisplay.textContent = "";
+  resultDisplay.textContent = "Purged!";
+  setTimeout(() => (resultDisplay.textContent = ""), 600);
+}
+
+// Functions for performing mathematical operations
+function add(a: number | string, b: number | string): number {
+  return parseFloat((+a + +b).toFixed(10));
+}
+
+function subtract(a: number | string, b: number | string): number {
+  return parseFloat((+a - +b).toFixed(10));
+}
+
+function multiply(a: number | string, b: number | string): number {
+  return parseFloat((+a * +b).toFixed(10));
+}
+
+function divide(a: number | string, b: number | string) {
+  if (b == "" || b == 0 || b == "0" || b == ".") {
+    handleError("InvalidDivisor");
+    return;
+  }
+  return parseFloat((+a / +b).toFixed(10));
+}
+
+function percentage(a: number | string) {
+  return +a / 100;
+}
+
+function performOperation() {
+  switch (calculator.operator) {
+    case "+":
+      calculator.result = `${add(calculator.firstOperand, calculator.secondOperand)}`;
+      calculator.firstOperand = "";
+      calculator.secondOperand = "";
+      calculator.operator = "";
+      break;
+    case "-":
+      calculator.result = `${subtract(calculator.firstOperand, calculator.secondOperand)}`;
+      calculator.firstOperand = "";
+      calculator.secondOperand = "";
+      calculator.operator = "";
+      break;
+    case "*":
+      calculator.result = `${multiply(calculator.firstOperand, calculator.secondOperand)}`;
+      calculator.firstOperand = "";
+      calculator.secondOperand = "";
+      calculator.operator = "";
+      break;
+    case "/":
+      calculator.result = `${divide(calculator.firstOperand, calculator.secondOperand)}`;
+      calculator.firstOperand = "";
+      calculator.secondOperand = "";
+      calculator.operator = "";
+      break;
+  }
+  if (calculator.result.length > 9) {
+    changeFontSize("change");
+  }
+  if (calculator.result.length > MAX_RESULT_LENGTH) {
+    handleError("ResultLengthExceeded");
+  }
+}
+
+// Functions for handling errors
+function handleError(error: string) {
+  switch (error) {
+    case "NoInputOperation":
+      displayError("Error: Enter a number first!");
+      break;
+    case "InputLengthExceeded":
+      displayError("Error: Length exceeded!");
+      break;
+    case "NoOperatorChosen":
+      displayError("Error: No operator chosen!");
+      break;
+    case "InvalidDivisor":
+      displayError("Error: Invalid divisor!");
+      break;
+    case "EmptyCalculatorObject":
+      displayError("Error: Enter a pair of numbers first!");
+      break;
+    case "ResultLengthExceeded":
+      displayError("Error: Cannot calculate!");
+      break;
+    default:
+      displayError("Error!");
+      break;
+  }
+}
+
+function displayError(string: string) {
+  expressionDisplay.textContent = "";
+  changeFontSize("change");
+  resultDisplay.textContent = string;
+  setTimeout(() => {
+    resultDisplay.textContent = "";
+    expressionDisplay.textContent = "";
+    changeFontSize("reset");
+  }, 700);
+}
+
+// Functions for displaying text on the display of the calculator UI
+function logExpression(operator: string) {
+  if (operator == "=") {
+    if (calculator.result == "undefined" || calculator.result == "NaN") {
+      return;
+    } else {
+      expressionDisplay.append(`${resultDisplay.textContent!}`);
+      return;
+    }
+  }
+  expressionDisplay.append(`${resultDisplay.textContent!}${operator}`);
+  resultDisplay.textContent = "";
+}
+
+function changeFontSize(string: string) {
+  if (string == "change") {
+    resultDisplay.style.fontSize = "30px";
+    return;
+  } else {
+    resultDisplay.style.fontSize = "";
+  }
+}
+
+// Prevent right-clicking
+document.addEventListener("contextmenu", (e) => e.preventDefault());
+window.addEventListener("load", () => {
+  resultDisplay.textContent = "Hello!";
+  setTimeout(() => (resultDisplay.textContent = ""), 700);
+});
+
+// Keyboard support
+document.addEventListener("keydown", (event) => {
+  if (event.key === "Enter") {
+    event.preventDefault();
+  }
+  // Handle input buttons
+  switch (event.key) {
+    case "0":
+      inputBtnClicked("0");
+      break;
+    case "1":
+      inputBtnClicked("1");
+      break;
+    case "2":
+      inputBtnClicked("2");
+      break;
+    case "3":
+      inputBtnClicked("3");
+      break;
+    case "4":
+      inputBtnClicked("4");
+      break;
+    case "5":
+      inputBtnClicked("5");
+      break;
+    case "6":
+      inputBtnClicked("6");
+      break;
+    case "7":
+      inputBtnClicked("7");
+      break;
+    case "8":
+      inputBtnClicked("8");
+      break;
+    case "9":
+      inputBtnClicked("9");
+      break;
+    case ".":
+      inputBtnClicked(".");
+  }
+
+  // Handle Operation buttons
+  switch (event.key) {
+    case "+":
+      handleOperatorClick("+");
+      break;
+    case "-":
+      handleOperatorClick("-");
+      break;
+    case "*":
+      handleOperatorClick("*");
+      break;
+
+    case "/":
+      handleOperatorClick("/");
+      break;
+    case "%":
+      percentageBtnClicked();
+      break;
+    case "=":
+    case "Enter":
+      equalsBtnClicked();
+      break;
+  }
+
+  // Handle other buttons
+  switch (event.key) {
+    case "Backspace":
+    case "Escape":
+      clearButtonClicked();
+      break;
+    case "Delete":
+      deleteButtonClicked();
+      break;
+  }
+});