如何替换字符串中的子字符串，并获得包含替换子字符串的完整字符串?

Question

如何替换字符串中的子字符串，并获取包含替换子字符串的完整字符串？

string ex1 = "Example1";
string output;
for (int i = 0; i <= ex1.Lenght; i++)
{
if (ex1.Substring(i, 1).Contains("1")
{
output = ex1.Substring(i, 1).Replace("1", "!");
} // output is here ! but i want the complete string with the Replaced substring, like "Example!"
}
Console.WriteLine(output);

Answer 1

String.Replace自己做你想做的事 - 不需要子字符串：

string output = ex1.Replace("1", "!");