//fffff
char [] a = {"1","2","3"}string b = new string(a)string[] a = {"1","2","3"}string b = String.Join("",a)String类的属性与方法属性:字符数量, Length
a:"11112222"b:"12"Compare(a,b)返回相对位置Concat(a,b)拼接两个字符串Concat(a,b,c)