CODEWITHSUNDEEP
c#string
user3050215
user3050215

Reputation: 197

Make a string out of a single tab character

I want to create a string that consists of a single character such as '\t' and that's it, however the String class constructor won't accept it. 

String myTab = new String( '\t' );

This gave me:

Error 2 Argument 1: cannot convert from 'char' to 'char*'

Okay, I thought I wouldn't need pointers after switching from C++, but I'll give you one then:

char oneChar = '\t';     
String myTab = new String( &oneChar );

Gives:

Error 1 Pointers and fixed size buffers may only be used in an unsafe context

So I tried this clumsy conversion instead without success:

String myTab = new String( ToString('\t') );

The error I get here is:

Error 3 Argument 1: cannot convert from 'string' to 'char[]'

This is the simplest issue ever and it irritates me a lot. Can anybody tell me how to solve it and why the string class isn't made to accept single characters?

Upvotes: 0

Views: 366

Answers (4)

Nicholas Carey
Nicholas Carey

Reputation: 74277

You can do what you want in a number of ways. Just off the top of my head, that includes (but probably isn't limited to):

string s1 = '\t'.ToString() ;
string s2 = new string( new char[]{'\t'} ) ;
string s3 = new string( '\t' , 1 ) ;
string s4 = new StringBuilder().Append('\t').ToString() ;

Or, since you already know the character in question:

string s5 = "\t" ;

I suspect that all of the 1st 4 will likely be optimized away into the 5th form.

Upvotes: 0

spender
spender

Reputation: 120480

char and string are different data types. You can't use a char where a string is expected (or for that matter, where a char* or char[] are expected).

The constructor that takes char* can only be used in an unsafe context (see other answers), but unless you've got a real good reason for going unsafe, don't do it (however tempting it is with your C++ background).

'\t' defines a char

"\t" defines a one character string

As such wouldn't

string myString = "\t";

be fine?

If you want to convert a char into a string

string myString = myChar.ToString();

Upvotes: 7

Simon Whitehead
Simon Whitehead

Reputation: 65079

While spender's answer addresses your main issue, I thought I might answer your issue with the pointer.

The error Pointers and fixed size buffers may only be used in an unsafe context means that you need to tell the compiler you're using potentially unsafe code, by wrapping it in an unsafe block:

unsafe {
    char oneChar = '\t'; 

    String myTab = new String( &oneChar ); 
}

..would then be fine.

But, you also need to let the compiler know that you're going to be using unsafe code by enabling it in the project settings:

Enable unsafe code

Upvotes: 1

BradleyDotNET
BradleyDotNET

Reputation: 61349

You don't normally "instantiate" a string object, and you certainly don't assign a string to a char.

The following will compile:

String test = "\t";

This is the normal way of doing what you ask.

Upvotes: 2

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