C#字符串类的典型用法

using System;
namespace e1_4_11
{
class Program
{
static void Main(string[] args)
{
//字符串搜索
string s = "ABC科学";
int j = s.IndexOf("科");
Console.WriteLine("{0}", j);

string s1 = "abc";
string s2 = "abc";
string s3 = "相同";
//判断连个字符串是否相同
if (s1 == s2)
Console.WriteLine("{0}", s3);
else
{
s3 = "不相同";
Console.WriteLine("{0}", s3);
}

//判断字符串是否为空
string s4 = "";
string s5 = "不空";
if (s4.Length == 0)
{
s5 = "空";
Console.WriteLine("{0}", s5);
}

string s6 = "取子字符串";
//从索引为2开始取2个字符，sb="字符",s内容不变
string sb = s6.Substring(2, 2); //sb="字符"
char sb1 = s6[0];
Console.WriteLine(sb);
Console.WriteLine(sb1);

//删除字符串
string sb2 = s6.Remove(0, 2); //从索引为0开始删除2个字符，sb="字符串",s6内容不变
Console.WriteLine(sb2);

//插入字符串
string s7 = "计算机科学";
string s8 = s7.Insert(3, "软件");
Console.WriteLine(s8);

//替换字符串
string s9 = s7.Replace("计算机", "软件");
Console.WriteLine(s9);

//将字符串转换为字符数组
char[] s10 = s7.ToCharArray(0, s7.Length);
Console.WriteLine(s10);

//转换为字符串
int i = 9;
string s11 = i.ToString();
Console.WriteLine(s11);

//大小写转换
string st = "AaBbCc";
string s12 = st.ToLower();
string s13 = st.ToUpper();
Console.WriteLine(s12);
Console.WriteLine(s13);

//删除所有空格
string sk = "A   bc";
Console.WriteLine(sk.Trim());
}
}
}