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I am trying to add spaces to end of a string in C#:

Trip_Name1.PadRight(20);

Also tried:

Trip_Name1.PadRight(20,' ');

None of this seems to work. However I can pad the string with any other character. Why?

I should have been more specific, here is full code:

lnk_showmatch_1.Text = u_trip.Trip_Name1.PadRight(20,' ');
CharithJ
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Bruce
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    What is `Trip_Name1` in your tests? What is the return value of those methods (i.e. what does *"doesn't seem to work"* mean)? And you're aware that these methods won't modify the value of `Trip_Name1`, right? – Michael Petrotta Sep 05 '11 at 03:35
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    Can you provide the code sample? By the way, strings are immutable and you have to reassign the result value after padding – default locale Sep 05 '11 at 03:36
  • I should have been more specific, here is full code: lnk_showmatch_1.Text = u_trip.Trip_Name1.PadRight(20,' '); – Bruce Sep 05 '11 at 03:50

2 Answers2

29

String are immutable, they cannot be changed. PadRight returns a new instance of the string padded, not change the one it was called from. What you want is this:

Trip_Name1 = Trip_Name1.PadRight(20,' ');

There is a great discussion on this StackOverflow question as to why strings are immutable.

EDIT:

None of this seems to work. However I can pad the string with any other character.

Are you actually re-assigning it like the example above? If that is the case - then without more detail I can only think of the following:

  1. If you are storing this in a database and retrieving it, some databases with the correct settings may "Trim" for you.
  2. You have logic somewhere else that is trimming the white-spaces. This is common when dealing with user input.

EDIT 2:

I should have been more specific

I'm going to take a wild guess based on your naming conventions that you are dealing with HTML / ASP.NET. In most cases, in HTML - white space is collapsed. For example:

<div><a>Hello           World</a></div>
<div><a>Hello World</a></div>

Both of the a tags will render the same because the white-space is being collapsed. If you are indeed working with HTML - that is likely your reason and why the padding works for all other characters. If you do a view-source of the markup rendered - does it contain the additional white spaces?

If you wanted to keep the whitespaces, try applying a CSS style on your element called white-space and set it to pre. For example:

<a style="white-space:pre">hello     world      </a>

That will cause the white-space to be preserved. Keep in mind that using white space like this has disadvantages. Browsers don't render them identically, etc. I wouldn't use this for layout purposes. Consider using CSS and something like min-width instead.

Community
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vcsjones
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  • @user554134 - I've made a few more edits based on your update. – vcsjones Sep 05 '11 at 03:55
  • Does not work for me too. Same problem var str = INRECField.PadRight(11, ' ') + INRECDate?.ToString("MMddyy") + INRECModel.PadRight(12, ' ') + INRECSerial.PadRight(14, ' ') + INRECAccessCode.PadRight(5, ' '); str = str.PadRight(32, ' '); – user2831855 Feb 10 '16 at 01:10
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Keep in mind, that way won't work for any string manipulation functionality because string is immutable. They just return a new string rather than updating the existing instance.

PadRight returns a new string that left-aligns the characters in this string by padding them on the right with a specified Unicode character, for a specified total length.

string Trip_Name1 = Trip_Name1.PadRight(20,' ');

EDIT:

Your control seems to be trimming the ending spaces. So, try to set the padding for the control rather than for the text.

CharithJ
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