C#单行输入控制台计算器开发求助：支持多运算符连续计算

我正在开发一款控制台小型计算器，要求用户在控制台单行输入运算表达式，例如输入"88+12*7/2"需按照从左到右依次计算的逻辑（即转换为((88+12)*7)/2）并输出结果。目前已完成部分代码，但仅支持两个数字的运算，需要协助完善代码。

已实现的代码 #

static string Input_User()
{
    string Input_User = Console.ReadLine();
    return Input_User;
}
static void ShowMessage()
{
    Console.WriteLine("Enter your numbers with operation like: 7*7");
}
ShowMessage();
string input_string = Input_User();
int result = PerformCalculation(InputToList(input_string));
Console.WriteLine($"{input_string}={result}");

static string[] InputToList(string input)
{
    string number1 = "";
    string number2 = "";
    string Oprt = "";
    string[] Arithmetic = new string[3];
    int n = 0;
    foreach (char charecter in input)
    {
        int num;
        bool isNumerical = int.TryParse(charecter.ToString(), out num);
        n += 1;
        if (isNumerical)
        {
            number1 += num;
        }
        else
        {
            Oprt = charecter.ToString();
            Arithmetic[0] = number1;
            Arithmetic[1] = Oprt;
            for (int i = n; i <= input.Length - 1; i++)
            {
                number2 += input[i];
            }
            Arithmetic[2] = number2;
        }

    }
    return Arithmetic;
}

static int PerformCalculation(string[] Input)
{
    int result = 0;
    switch (Input[1])
    {
        case "+":
            result = Int32.Parse(Input[0]) + Int32.Parse(Input[2]);
            break;
        case "-":
            result = Int32.Parse(Input[0]) - Int32.Parse(Input[2]);
            break;
        case "*":
            result = Int32.Parse(Input[0]) * Int32.Parse(Input[2]);
            break;
        case "/":
            result = Int32.Parse(Input[0]) / Int32.Parse(Input[2]);
            break;
    }
    return result;
}

完善方案 #

原代码仅能处理两个数字的表达式，要支持多数字连续运算，需要修改核心逻辑：拆分表达式为数字和运算符列表，再按左到右顺序逐步计算。

1. 重构表达式拆分方法 #

将原InputToList改为拆分所有数字和运算符，分别存入列表，方便迭代计算：

static (List<int> numbers, List<char> operators) ParseExpression(string input)
{
    var numbers = new List<int>();
    var operators = new List<char>();
    string currentNumber = "";

    foreach (char c in input)
    {
        if (char.IsDigit(c))
        {
            currentNumber += c;
        }
        else if ("+-*/".Contains(c))
        {
            if (int.TryParse(currentNumber, out int num))
            {
                numbers.Add(num);
                currentNumber = "";
                operators.Add(c);
            }
            else
            {
                throw new ArgumentException("无效的数字格式");
            }
        }
        else
        {
            throw new ArgumentException($"不支持的字符: {c}");
        }
    }

    if (int.TryParse(currentNumber, out int lastNum))
    {
        numbers.Add(lastNum);
    }
    else
    {
        throw new ArgumentException("表达式结尾无效");
    }

    return (numbers, operators);
}

2. 重构计算方法 #

按左到右顺序，每次取前两个数字和第一个运算符计算，用结果替换原位置，直到只剩一个结果：

static int PerformCalculation((List<int> numbers, List<char> operators) expression)
{
    var nums = new List<int>(expression.numbers);
    var ops = new List<char>(expression.operators);

    while (nums.Count > 1)
    {
        int num1 = nums[0];
        int num2 = nums[1];
        char op = ops[0];

        int tempResult = op switch
        {
            '+' => num1 + num2,
            '-' => num1 - num2,
            '*' => num1 * num2,
            '/' => num2 == 0 ? throw new DivideByZeroException("不能除以零") : num1 / num2,
            _ => throw new ArgumentException($"不支持的运算符: {op}")
        };

        nums.RemoveRange(0, 2);
        nums.Insert(0, tempResult);
        ops.RemoveAt(0);
    }

    return nums[0];
}

3. 调整主程序逻辑 #

更新主代码，调用新方法并添加异常处理：

static void ShowMessage()
{
    Console.WriteLine("Enter your numbers with operation like: 88+12*7/2");
}

ShowMessage();
string input_string = Console.ReadLine();

try
{
    var expression = ParseExpression(input_string);
    int result = PerformCalculation(expression);
    Console.WriteLine($"{input_string}={result}");
}
catch (Exception ex)
{
    Console.WriteLine($"错误: {ex.Message}");
}

完整代码 #

using System;
using System.Collections.Generic;

class Calculator
{
    static void Main()
    {
        ShowMessage();
        string input_string = Console.ReadLine();

        try
        {
            var expression = ParseExpression(input_string);
            int result = PerformCalculation(expression);
            Console.WriteLine($"{input_string}={result}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"错误: {ex.Message}");
        }
    }

    static void ShowMessage()
    {
        Console.WriteLine("Enter your numbers with operation like: 88+12*7/2");
    }

    static (List<int> numbers, List<char> operators) ParseExpression(string input)
    {
        var numbers = new List<int>();
        var operators = new List<char>();
        string currentNumber = "";

        foreach (char c in input)
        {
            if (char.IsDigit(c))
            {
                currentNumber += c;
            }
            else if ("+-*/".Contains(c))
            {
                if (int.TryParse(currentNumber, out int num))
                {
                    numbers.Add(num);
                    currentNumber = "";
                    operators.Add(c);
                }
                else
                {
                    throw new ArgumentException("无效的数字格式");
                }
            }
            else
            {
                throw new ArgumentException($"不支持的字符: {c}");
            }
        }

        if (int.TryParse(currentNumber, out int lastNum))
        {
            numbers.Add(lastNum);
        }
        else
        {
            throw new ArgumentException("表达式结尾无效");
        }

        return (numbers, operators);
    }

    static int PerformCalculation((List<int> numbers, List<char> operators) expression)
    {
        var nums = new List<int>(expression.numbers);
        var ops = new List<char>(expression.operators);

        while (nums.Count > 1)
        {
            int num1 = nums[0];
            int num2 = nums[1];
            char op = ops[0];

            int tempResult = op switch
            {
                '+' => num1 + num2,
                '-' => num1 - num2,
                '*' => num1 * num2,
                '/' => num2 == 0 ? throw new DivideByZeroException("不能除以零") : num1 / num2,
                _ => throw new ArgumentException($"不支持的运算符: {op}")
            };

            nums.RemoveRange(0, 2);
            nums.Insert(0, tempResult);
            ops.RemoveAt(0);
        }

        return nums[0];
    }
}

功能说明 #

• 支持多数字连续运算，严格按左到右顺序计算（如88+12*7/2会得到350）
• 增加异常处理，覆盖无效字符、无效数字、除零错误等场景
• 代码结构更清晰，拆分与计算逻辑分离，便于后续扩展

内容的提问来源于stack exchange，提问作者Slahtalab mohsen