How can i put this symbol (€) on the terminal using c. I've tried:
printf("%c",0128);
0128 is the code on the ascii table but the compiller gives the error:
invalid digit 8 in octal constant
CodePudding user response：
Numeric literals that begin with 0 like that, are interpreted as octal (base 8) and therefore comprised solely of digits from 0-7. So 08 is illegal, and so is 0128.
Windows-1252 (CP-1252) encoding of the euro sign € is decimal 128.
What you have posted an image of is the Alt code which is a way of entering the character on Windows by typing: Alt0128 on the numeric key pad.
You may be able to fix your problem by removing the leading zero (to produce the decimal literal 128), provided you are using CP-1252.
CodePudding user response：
You're confusing a few things here.
First, the table of which you posted a fragment does not show character codes. It apparently documents how to enter characters on Windows (I covered this in a reply to another question here: C# Mapping ALT <XXX> codes to characters). The leading zero here means that the character code you're entering refers to the so-called ANSI codepage instead of OEM one.
Note that the character you get by typing Alt 0128 may vary from computer to computer.
Also note that 128 is not an ASCII code. ASCII only covers character codes 0 to 127.
Second, leading zero in an integer literal in C and its successors has a different meaning. It means that the number is written in the octal numeral system. Octal notation was more popular than hexadecimal back in 70s when C was drafted. By definition, 8 is not a valid octal digit, so 0128 is a lexical error.
These two meanings are unrelated. So, if you want to print a character that is entered by the key combination Alt 0128, you need to do that otherwise.
Also note that in many cases you cannot have € expressed as one char unit. If your console is configured to UTF-8, then the Unicode codepoint for it, 0x20AC, is represented by three bytes: 0xe2, 0x82, 0xac (or 226, 130, 172).
CodePudding user response：
The best way to print stuff like that is... don’t use hex/oct/whatever constants, use a string.
Use your text editor’s ability to save source code as UTF-8 and do that directly:
puts( "Dinner is €12.50." );
Assuming:
- Compiler takes UTF-8 source input (modern compilers do, older compilers might require a flag)
- The standard library handles UTF-8 (it better these days)
- A terminal that can display UTF-8
That last one is the sticking point. Most modern systems work over UTF-8 display, but the old Windows Console is still in use in a lot of places, and that requires a little extra help. Make sure to have it working in UTF-8 output mode (chcp 65001 on the command-line or the equivalent in code using SetConsoleOutputCP).