I have the following strings:
var temp = null;
var temp = "";
var temp = "12345678";
var temp = "1234567890";
What I need to do is if have a function that will give me the last four digits of the input variable if the input variable is 8 or 10 characters long. Otherwise I need it to return "";
Is there an easy way I can do this in C#. I am just not sure how to deal with null because if I get the length of null then I think that will give me an error.
int length = (temp ?? "").Length;
string subString = "";
if(length == 8 || length == 10)
{
subString = temp.Substring(length - 4);
}
You can use IsNullOrEmpty, As if string is null or Empty then substring is not possible.
if (!String.IsNullOrEmpty(str) && (str.Length == 8 || str.Length == 10))
{
string substr = str.Substring(str.Length-4);
}
Try this
string YourFunctionName(string input)
{
string rVal = "";
if (string.IsNullOrEmpty(input))
return rVal;
if (input.Length == 8 || input.Length == 10)
rVal = input.Substring(input.Length - 4);
return rVal;
}
I would likely write it like this, if writing a function:
string GiveMeABetterName (string input) {
if (input != null
&& (input.Length == 8 || input.Length == 10)) {
return input.Substring(input.Length - 4);
} else {
return "";
}
}
As can be seen by all the answers, there is multiple ways to accomplish this.