script.js

/**
 * Calculator Logic v3
 * Handles mathematical operations, UI updates, and floating-point precision fixes.
 *
 * @author Claudio Borromei
 * @version 3.0
 */

let input = document.getElementById('inputBox');
let button = document.querySelectorAll('button');

let string = "";
let isResultDisplayed = false;
const operators = ['+', '-', '*', '/', '%'];

let arrayButtons = Array.from(button);
arrayButtons.forEach(button => {
	button.addEventListener('click', (e) => {
		let btnText = e.target.innerHTML;

		if (btnText == '=') {

			let result = eval(string);

			// Fix floating-point imprecision (e.g., 0.1 + 0.2) by rounding to 10 decimal places
			string = Number(result.toFixed(10)).toString();
			input.value = string;
			isResultDisplayed = true;
		}

		else if (btnText == 'AC') {
			string = "";
			input.value = string;
		}

		else if (btnText == 'C') {
			string = string.substring(0, string.length - 1);
			input.value = string;
		}

		else if (operators.includes(btnText)) {
			const lastChar = string.slice(-1);

			if (operators.includes(lastChar)) {
				string = string.slice(0, -1) + btnText;
			}
			else {
				string += btnText;
			}
			input.value = string;
			isResultDisplayed = false;
		}

		else {
			if (isResultDisplayed == true) {
				string = btnText;
			}
			else {
				string += btnText;
			}
			input.value = string;
			isResultDisplayed = false;
		}

	})
})