static void Main()
{
//demo1 除去空格,提取出各个单词
string s = "a b c";
string[] word = s.Split(new char[] { ' ' });
foreach (string temp in word)
Console.WriteLine(temp);

//demo2 直接去除所有空格
s=s.Replace(" ","");
Console.WriteLine(s);

//demo3 去掉首尾空格
s = " aaa ";
s = s.Trim();
Console.WriteLine(s);
}