string[] strOperate=new string[]{"+","-","*","/"};
string str_in=Console.ReadLine();
foreach(string c in strOperate)
{
if(str_in ==c)
{
Console.writeline("输入符号正确!")
}
else
{
Console.writeline("输入符号错误!!!");
} }
string str_in=Console.ReadLine();
foreach(string c in strOperate)
{
if(str_in ==c)
{
Console.writeline("输入符号正确!")
}
else
{
Console.writeline("输入符号错误!!!");
} }
string[] strOperate=new string[]{"+","-","*","/"};
string str_in=Console.ReadLine();
st.AddRange(strOperate);
if(st.IndexOf(str_in)>-1) //(1)C#中能否这样判断,如同Delphi中一样????
{
Console.writeline("输入符号正确!")
}
else
{
Console.writeline("输入符号错误!!!");
}
else 不存在;
string strOperate = String.Concat(strs);
string str = Console.ReadLine();
if (strOperate.IndexOf(str) > -1)
{
Console.writeline("输入符号正确!");
}
else
{
Console.writeline("输入符号错误!!!");
}
if(Array.IndexOf(strOperate,str_in)〉-1)
List<string> strOperate = new List<string>();
strOperate.Add("+");
strOperate.Add("-");
strOperate.Add("*");
strOperate.Add("/");
string str_in = "/";
if (strOperate.IndexOf(str_in) != -1)
{
MessageBox.Show("ok");
}