C# 编程/关键字/else

关键字 else 用于标识else 子句，它属于一个 if 语句，其语法如下

if-statement ::= "if" "(" condition ")" if-body "else" else-body

condition ::= boolean-expression

if-body ::= statement-or-statement-block

else-body ::= statement-or-statement-block

一个 else 子句紧随一个 if-body。当 condition 为 false 时，它提供要执行的代码。如果将 else-body 设置为另一个 if 语句，则会创建一个常见的 if、else if、else if、else if、else 语句的级联

using System;

public class IfStatementSample
{
    public void IfMyNumberIs()
    {
        int myNumber = 5;
        if (myNumber == 4)
            Console.WriteLine("This will not be shown because myNumber is not 4.");
        else if(myNumber < 0)
        {
            Console.WriteLine("This will not be shown because myNumber is not negative.");
        }
        else if(myNumber%2 == 0)
            Console.WriteLine("This will not be shown because myNumber is not even.");
        else
        {
            Console.WriteLine("myNumber does not match the coded conditions, so this sentence will be shown!");
        }
    }
}

上面的例子只检查 myNumber 是否小于 0，前提是 myNumber 不等于 4。它依次只检查 myNumber%2 是否为 0，前提是 myNumber 不小于 0。由于所有条件都不成立，它会执行最终 else 子句的主体。

C# 关键字
abstract as base bool break byte case catch char checked class const continue decimal default delegate do double else enum event explicit extern false finally fixed float for foreach goto if implicit in int interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sbyte sealed short sizeof stackalloc static string struct switch this throw true try typeof uint ulong unchecked unsafe ushort using var virtual void volatile while
C# 特殊标识符（上下文关键字）
add alias async await dynamic get global nameof partial remove set value when where yield
上下文关键字（用于查询）
ascending by descending equals from group in into join let on orderby select where