编写程序实现计算机的四则运算

编写一个简单的计算机四则运算程序，通常涉及基本的算术操作如加法、减法、乘法和除法。这通常是在控制台应用或基于某种编程语言的环境中完成。这里以Python为例，你可以创建一个函数来处理每个运算：

def add(x, y):
    return x + y

def subtract(x, y):
    return x - y

def multiply(x, y):
    return x * y

def divide(x, y):
    if y != 0:
        return x / y
    else:
        print("Error: Division by zero is not allowed.")
        return None  # 或者抛出异常

# 用户输入
operator = input("Enter operator (+, -, *, /): ")
num1 = float(input("Enter first number: "))
num2 = float(input("Enter second number: "))

if operator == '+':
    result = add(num1, num2)
elif operator == '-':
    result = subtract(num1, num2)
elif operator == '*':
    result = multiply(num1, num2)
elif operator == '/':
    result = divide(num1, num2)
else:
    print("Invalid operator.")

print(f"Result of {num1} {operator} {num2} is: {result}")