string str = "132"+"456";
string str2 = str +"www";
console.writeline("www"+123);
string str = console .readline();
console.writeline(str +"-");
1 类型一致
2 右边的值所需要的容器大小,小于等于左边的容器
string a = Console.ReadLine();
int a1 = Convert.ToInt32(a);
string b = Console.ReadLine();
int b1 = Convert.ToInt32(b);
Console.WriteLine(a1+b1);
int a = console.readl