比较一个字符串和另一个字符串

Question

我有一个用户关于他们年龄的回复存储为int age;。然后我要求用户将他们的年龄除以某个数字，然后他们将该数字输入我的控制台。该号码存储为int rep;。从那里，我想问int rep; 是偶数还是奇数。我意识到您不能在 if () 语句中使用字符串。但是，我无法正确地提出我的问题以在网络上找到解决方案/帖子，这将帮助我了解如何检查我存储为字符串的用户输入是否可以与我期望的答案进行比较。

总而言之：对于字符串，if () 是否有等效的语法？

//Second task
int age;
int rep;


Console.WriteLine ("How old are you? ");
age = Convert.ToInt32 (Console.ReadLine ());
Console.WriteLine ("What is the your age divided by your first number submitted in the previous question? ");
rep = Convert.ToInt32 (Console.ReadLine ());
if (rep == age / num01 ) {
    Console.WriteLine ("That is correct. Proceed to the next question. ");
} else
{
    Console.WriteLine ("That is incorrect. Start over. ");
}
Console.WriteLine ();

//Third task
string ans;

Console.WriteLine ("Is your answer to the previous question an even or odd number? ");
ans = Console.ReadLine ();
if (rep % 2 == 0 && ans == even)
{
    Console.WriteLine ("That is correct. ");
}
if (rep % 2 == 1 && ans == odd) 
{
    Console.WriteLine ("That is correct. ");
}   

Answer 1

在你的情况下我会改变

ans = Console.ReadLine();

到这个。

ans = Console.ReadLine().ToLower();

然后将您的 ITE 更改为此。

if (rep % 2 == 0 && ans == "even") {//code here.}
else if (ans == "odd") {//code here.} // This should also be else if not just if. With it being else if the extra check rep % 2 == 1 is not needed.

或者，为了更好的字符串比较，您应该这样做。

ans = Console.ReadLine();
if (rep % 2 == 0 && ans.Equals("even", StringComparison.OrdinalIgnoreCase)) {//code here.}
else if (ans == ans.Equals("odd", StringComparison.OrdinalIgnoreCase)) {//code here.} // This should also be else if not just if. With it being else if the extra check rep % 2 == 1 is not needed. 

上面将检查比较并忽略字符串的大小写，因此您不需要使用 ToLower 并且使用 == 进行字符串比较的问题不应该出现。

感谢 Alexei Levenkov 指出这一点。

您还可以查看此内容以供将来在字符串比较方面参考。 https://msdn.microsoft.com/en-us/library/system.stringcomparison(v=vs.110).aspx

Answer 2

https://msdn.microsoft.com/en-us/library/system.string.op_equality%28v=vs.110%29.aspx

== 运算符适用于字符串，因此以下是使您的代码正常工作所需的修改

//Second task
int age;
int rep;


Console.WriteLine ("How old are you? ");
age = Convert.ToInt32 (Console.ReadLine ());
Console.WriteLine ("What is the your age divided by your first number submitted in the previous question? ");
rep = Convert.ToInt32 (Console.ReadLine ());
if (rep == age / num01 ) {
    Console.WriteLine ("That is correct. Proceed to the next question. ");
} 
else
{
    Console.WriteLine ("That is incorrect. Start over. ");
}
Console.WriteLine ();

//Third task
string ans;

Console.WriteLine ("Is your answer to the previous question an even or odd number? ");
ans = Console.ReadLine ();
//change 1
if (rep % 2 == 0 && ans == "even")
{
   Console.WriteLine ("That is correct. ");
}
//change2
if (rep % 2 == 1 && ans == "odd") 
{
    Console.WriteLine ("That is correct. ");
}