Delete last char of string
C#StringCharC# Problem Overview
I am retrieving a lot of information in a list, linked to a database and I want to create a string of groups, for someone who is connected to the website.
I use this to test but this is not dynamic, so it is really bad:
string strgroupids = "6";
I want to use this now. But the string returned is something like 1,2,3,4,5,
groupIds.ForEach((g) =>
{
strgroupids = strgroupids + g.ToString() + ",";
strgroupids.TrimEnd(',');
});
strgroupids.TrimEnd(new char[] { ',' });
I want to delete the ,
after the 5
but it's definitely not working.
C# Solutions
Solution 1 - C#
strgroupids = strgroupids.Remove(strgroupids.Length - 1);
MSDN: > String.Remove(Int32): > > Deletes all the characters from this string beginning at a specified > position and continuing through the last position
Solution 2 - C#
What about doing it this way
strgroupids = string.Join( ",", groupIds );
A lot cleaner.
It will append all elements inside groupIds
with a ','
between each, but it will not put a ','
at the end.
Solution 3 - C#
Strings in c# are immutable. When in your code you do strgroupids.TrimEnd(',');
or strgroupids.TrimEnd(new char[] { ',' });
the strgroupids
string is not modified.
You need to do something like strgroupids = strgroupids.TrimEnd(',');
instead.
To quote from here:
> Strings are immutable--the contents of a string object cannot be > changed after the object is created, although the syntax makes it > appear as if you can do this. For example, when you write this code, > the compiler actually creates a new string object to hold the new > sequence of characters, and that new object is assigned to b. The > string "h" is then eligible for garbage collection.
Solution 4 - C#
In C# 8 ranges and indices were introduced, giving us a new more succinct solution:
strgroupids = strgroupids[..^1];
Solution 5 - C#
Add an extension method.
public static string RemoveLast(this string text, string character)
{
if(text.Length < 1) return text;
return text.Remove(text.ToString().LastIndexOf(character), character.Length);
}
then use:
yourString.RemoveLast(",");
Solution 6 - C#
Removes any trailing commas:
while (strgroupids.EndsWith(","))
strgroupids = strgroupids.Substring(0, strgroupids.Length - 1);
This is backwards though, you wrote the code that adds the comma in the first place. You should use string.Join(",",g)
instead, assuming g
is a string[]
. Give it a better name than g
too !
Solution 7 - C#
Additional to sll's solution: It's better to trim the string in case there are some blank(s) at the end.
strgroupids = strgroupids.Remove(strgroupids.Trim().Length - 1);
Solution 8 - C#
As an alternate to adding a comma for each item you could just using String.Join:
var strgroupids = String.Join(",", groupIds);
This will add the seperator ("," in this instance) between each element in the array.
Solution 9 - C#
string strgroupids = string.Empty;
groupIds.ForEach(g =>
{
strgroupids = strgroupids + g.ToString() + ",";
});
strgroupids = strgroupids.Substring(0, strgroupids.Length - 1);
Note that the use of ForEach
here is normally considered "wrong" (read for example http://blogs.msdn.com/b/ericlippert/archive/2009/05/18/foreach-vs-foreach.aspx)
Using some LINQ:
string strgroupids = groupIds.Aggregate(string.Empty, (p, q) => p + q + ',');
strgroupids = strgroupids.Substring(0, str1.Length - 1);
Without end-substringing:
string strgroupids = groupIds.Aggregate(string.Empty, (p, q) => (p != string.Empty ? p + "," + q : q.ToString()));
Solution 10 - C#
string.Join
is better, but if you really want a LINQ ForEach
:
var strgroupids = string.Empty;
groupIds.ForEach(g =>
{
if(strgroupids != string.Empty){
strgroupids += ",";
}
strgroupids += g;
});
Some notes:
string.Join
andforeach
are both better than this, vastly slower, approach- No need to remove the last
,
since it's never appended - The increment operator (
+=
) is handy for appending to strings .ToString()
is unnecessary as it is called automatically when concatenating non-strings- When handling large strings,
StringBuilder
should be considered instead of concatenating strings
Solution 11 - C#
There is no "quick-and-dirty" way of doing this. I usually do:
mystring= string.Concat(mystring.Take(mystring.Length-1));
Solution 12 - C#
That code delete the last character in a string
string myString = "Hello;";
myString = myString.Remove(myString.Length-1);
Output
> Hello