Visual studio 2019 preview & C# 8 initial experience
using System;
using static System.Console;
namespace ConsoleApp2
{
class Program
{
static void Main(string[] args)
{
string s = null;
WriteLine(s.ToString());
WriteLine($"The first letter of {s} is {s[0]}");
}
}
}
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>netcoreapp3.0</TargetFramework>
<ApplicationIcon />
<StartupObject />
<AssemblyName>ConsoleApp1</AssemblyName>
<RootNamespace>ConsoleApp1</RootNamespace>
<LangVersion>8.0</LangVersion>
<NullableReferenceTypes>true</NullableReferenceTypes>
</PropertyGroup>
using System;
using static System.Console;
namespace ConsoleApp2
{
class Program
{
static void Main(string[] args)
{
string? s = null;
WriteLine($"The first letter of {s}is {s?[0] ?? '?'}");
}
}
}
转载于:https://www.cnblogs.com/xiexiaokui/p/10121591.html