68 lines
2.3 KiB
C#
68 lines
2.3 KiB
C#
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using System;
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namespace Lesson_One
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{
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class Program
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{
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static void Main(string[] args)
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{
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// ========== 变量 ==========
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int age = 25;
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double height = 175.5;
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string name = "无言势字幕";
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char grade = 'A';
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bool isActive = true;
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Console.WriteLine("=== 变量 ===");
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Console.WriteLine($"姓名: {name}");
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Console.WriteLine($"年龄: {age}");
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Console.WriteLine($"身高: {height}cm");
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Console.WriteLine($"等级: {grade}");
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Console.WriteLine($"状态: {isActive}");
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// ========== var 自动推断 ==========
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Console.WriteLine("\n=== var 自动推断 ===");
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var message = "这是 string 类型";
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var number = 42; // 推断为 int
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Console.WriteLine($"message 是: {message.GetType()}");
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Console.WriteLine($"number 是: {number.GetType()}");
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// ========== 常量 ==========
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Console.WriteLine("\n=== 常量 ===");
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const int MAX_RETRY = 3;
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const string VERSION = "v1.0";
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Console.WriteLine($"最大重试次数: {MAX_RETRY}");
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Console.WriteLine($"版本: {VERSION}");
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// ========== 类型转换 ==========
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Console.WriteLine("\n=== 类型转换 ===");
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int i = 10;
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double d = i; // 隐式转换
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Console.WriteLine($"int -> double: {d}");
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double d2 = 3.14;
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int i2 = (int)d2; // 显式转换
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Console.WriteLine($"double -> int: {i2}");
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string s = i.ToString();
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Console.WriteLine($"int -> string: {s}");
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int i3 = int.Parse("123");
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Console.WriteLine($"string \"123\" -> int: {i3}");
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// ========== 输入练习 ==========
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Console.WriteLine("\n=== 输入练习 ===");
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Console.Write("请输入你的名字: ");
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string inputName = Console.ReadLine();
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Console.Write($"你好, {inputName}! ");
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Console.Write("请输入年龄: ");
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string ageInput = Console.ReadLine();
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int userAge = int.Parse(ageInput);
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Console.WriteLine($"你 {userAge} 岁了");
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Console.ReadLine();
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}
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}
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}
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