console.writeline和readline
时间: 2023-05-01 13:03:38 浏览: 105
console.writeline 和 readline 是编程语言中常用的指令。console.writeline是用于输出文本或变量到命令行窗口或控制台的指令,readline则是用于从命令行窗口或控制台获取用户输入的指令。在很多编程语言中,这两个指令都是非常重要的基础操作。
相关问题
优化代码 Console.WriteLine("Please enter a number:"); int number = int.Parse(Console.ReadLine()); while (number <= 0) { Console.WriteLine("Sorry,please enter a positive value."); number = Int32.Parse(Console.ReadLine()); } Console.WriteLine("Please enter " + number + " words:"); string[] words = new string[number]; for (int n = 0; n < number; n++) { Console.WriteLine($"Please enter word {n + 1}"); string word = Console.ReadLine(); while (word.Length < 1) { Console.WriteLine("Sorry,your word must have at least one character"); word = Console.ReadLine(); } words[n] = word; } Console.WriteLine("You enter these words:"); foreach (string s in words) { Console.WriteLine(s); }; Console.WriteLine("Please enter a character:"); char letter = char.Parse(Console.ReadLine()); if (char.IsLetter(letter)) { string joinedWords = string.Join("", words).ToLower(); int count = 0; for (int i = 0; i < joinedWords.Length; i++) { if (joinedWords[i] == letter) { count++; } } if (count == 0) { Console.WriteLine("The letter you entered does not appear"); } else { double per = Convert.ToDouble(count) / Convert.ToDouble(joinedWords.Length); if (per > 0.25) { Console.WriteLine("The letter " + letter + " appears " + count + " times in the array. This letter makes up more than 25 % of the total number of characters."); } else { Console.WriteLine("The letter " + letter + " appears " + count + " times in the array. This letter makes up less than 25 % of the total number of characters."); } } } else { Console.WriteLine("Incorrect letter format entered,Please enter again:"); letter = char.Parse(Console.ReadLine()); }
以下是优化后的代码:
Console.WriteLine("Please enter a positive integer:");
int number;
while (!int.TryParse(Console.ReadLine(), out number) || number <= 0)
{
Console.WriteLine("Invalid input. Please enter a positive integer:");
}
string[] words = new string[number];
for (int i = 0; i < number; i++)
{
Console.WriteLine($"Please enter word {i + 1}:");
string word;
while (string.IsNullOrWhiteSpace(word = Console.ReadLine()))
{
Console.WriteLine("Invalid input. Please enter a non-empty word:");
}
words[i] = word;
}
Console.WriteLine("You entered these words:");
Console.WriteLine(string.Join(", ", words));
Console.WriteLine("Please enter a character:");
char letter;
while (!char.TryParse(Console.ReadLine(), out letter) || !char.IsLetter(letter))
{
Console.WriteLine("Invalid input. Please enter a letter:");
}
string joinedWords = string.Concat(words).ToLower();
int count = joinedWords.Count(c => c == letter);
if (count == 0)
{
Console.WriteLine($"The letter {letter} does not appear.");
}
else
{
double per = (double)count / joinedWords.Length;
if (per > 0.25)
{
Console.WriteLine($"The letter {letter} appears {count} times in the array. This letter makes up more than 25% of the total number of characters.");
}
else
{
Console.WriteLine($"The letter {letter} appears {count} times in the array. This letter makes up less than 25% of the total number of characters.");
}
}
主要进行了以下优化:
1. 使用 TryParse 进行输入验证,避免程序崩溃;
2. 使用 string.IsNullOrWhiteSpace() 进行字符串输入验证,避免用户输入空格或空字符串;
3. 使用 Count() 方法和 lambda 表达式计算字符出现次数;
4. 使用 string.Join() 方法和 string.Concat() 方法拼接字符串;
5. 简化了部分代码,并去除了不必要的类型转换。
这段代码为什么会出错 int sss; int ds; Console.WriteLine("qing shuru mima"); sss = int.Parse(Console.ReadLine()); if (sss == 88888888) { Console.WriteLine("zheng qu"); } else if (sss != 88888888) { Console.WriteLine("qingcxingshuru"); ds = int.Parse(Console.ReadLine()); if (ds == 88888888) ; { Console.WriteLine("zhengqu"); else { Console.WriteLine("cuowu"); } }
这段代码会出错的原因是因为在 if 语句中,第一个分支的末尾多了一个分号,导致后面的 else 分支被当成了一个独立的语句。正确的代码应该是:
```
int sss;
int ds;
Console.WriteLine("qing shuru mima");
sss = int.Parse(Console.ReadLine());
if (sss == 88888888)
{
Console.WriteLine("zheng qu");
}
else if (sss != 88888888)
{
Console.WriteLine("qingcxingshuru");
ds = int.Parse(Console.ReadLine());
if (ds == 88888888)
{
Console.WriteLine("zhengqu");
}
else
{
Console.WriteLine("cuowu");
}
}
```
注意到第 13 行的分号已经被删除了。