I want to replace the character 'A' of the first character of a string if the first character is 0.
Data 01234500
Expected output A1234500
code
results getting - A12345AA
string formattedId = "01234500";
if(formattedId.Substring(0,1)=="0")
formattedId = formattedId.Replace("0","A");
Console.WriteLine(formattedId);
The Replace() method always changes ALL instances of the targeted string. Instead, you can do this:
string formattedId = "01234500";
if(formattedId[0] == '0')
{
formattedId = "A" + formattedId.Substring(1);
}
Console.WriteLine(formattedId);
formattedId[0] is only a character, not a string, which is why my answer has single quotes on the right-hand side of the equality expression. This will be significantly more efficient than the StartsWith() option.You can use StartsWith() to check the first char and Substring(1) to get the part after first char:
string formattedId = "01234500";
if (formattedId?.StartsWith("0") is true)
{
formattedId = "A" + formattedId.Substring(1);
}
Console.WriteLine(formattedId); // Output: A1234500
