Operations Between Numbers

function operationNumbers(input) {
    let first_number = Number(input[0]);
    let second_number = Number(input[1]);
    let operator = input[2];
    // "+", "-", "*", "/", "%"
    let result;
    let evenOrOdd;
    if (operator == "+" || operator == "-" || operator == "*") {
        switch (operator) {
            case "+":
                result = first_number + second_number;
                if (result % 2 === 0) {
                    evenOrOdd = "even";
                } else {
                    evenOrOdd = "odd";
                }
                console.log(`${first_number} ${operator} ${second_number} = ${result} - ${evenOrOdd}`);
                break;
            case "-":
                result = first_number - second_number;
                if (result % 2 === 0) {
                    evenOrOdd = "even";
                } else {
                    evenOrOdd = "odd";
                }
                console.log(`${first_number} ${operator} ${second_number} = ${result} - ${evenOrOdd}`);
                break;
            case "*":
                result = first_number * second_number;
                if (result % 2 === 0) {
                    evenOrOdd = "even";
                } else {
                    evenOrOdd = "odd";
                }
                console.log(`${first_number} ${operator} ${second_number} = ${result} - ${evenOrOdd}`);
            default:
                break;
        }
    } else if (operator == "%") {
        if (second_number === 0) {
            console.log(`Cannot divide ${first_number} by zero`);
        } else {
            result = first_number % second_number;
        console.log(`${first_number} % ${second_number} = ${result}`);
        }
    } else if (operator == "/") {
        if (second_number === 0) {
            console.log(`Cannot divide ${first_number} by zero`);
        } else {
            result = first_number / second_number;
            console.log(`${first_number} / ${second_number} = ${result.toFixed(2)}`);
        }
    }
}