ASCII 227
Lowercase a with tildeGreek small pi
ASCII 227 is ã on Windows and π in old DOS.
ã (Small A with Tilde) is byte 227 in Windows-1252, Unicode U+00E3. Portuguese can't do without it (não, mãe, São Paulo), and Vietnamese and Guarani use it too. Code page 437 had no ã at all, so Portuguese DOS systems used code page 850, which put ã on byte 198, or the Portuguese code page 860, which put it on byte 132, where 437 has ä. That's why a Brazilian code page 860 file opened as code page 437 says näo instead of não. In UTF-8, ã is C3 A3, which misreads as ã. The HTML entity is ã.
π (Pi) is byte 227 in code page 437, the original IBM PC character set, and maps to Unicode U+03C0. It's the circle constant in formulas like A = πr², and JavaScript and Python both accept it as a variable name, so const π = Math.PI is legal code. Its capital Π (U+03A0) has a lookalike in the product sign ∏ (U+220F). For a product over a range use ∏, which is drawn at operator size, while Π is sized as a letter. Code page 850 put Ò on this byte. In UTF-8, π is CF 80, and the HTML entity is π.
Technical Details
Technical Details
Code Example
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#include <stdio.h>int main(void) {/* On Windows (code page 1252) byte 227 is ã.Modern terminals expect UTF-8, so print the code point, not the byte. */printf("\u00E3\n"); /* UTF-8: C3 A3 */unsigned char b = 227; /* the raw Windows-1252 byte */printf("%d 0x%02X\n", b, b); /* 227 0xE3 */return 0;}
Code Example
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#include <stdio.h>int main(void) {/* Byte 227 is π only on a console using code page 437(chcp 437 on Windows, or DOSBox). On a UTF-8 terminal thelone byte 0xE3 is invalid and prints as garbage, often �. */putchar(227);/* char is signed on x86, so a plain char holding 0xE3 is -29.Use unsigned char when you compare or index by byte value. */char c = (char)227;unsigned char u = 227;printf("\n%d %d\n", c, u); /* -29 227 *//* Portable: print the Unicode character as UTF-8 instead. */printf("\u03C0\n"); /* CF 80 */return 0;}
How to Type It
- Windows
- Hold Alt and type 0227 on the numeric keypad, with Num Lock on. The leading zero picks the Windows code page. No numeric keypad? In Word, type 00E3 and press Alt+X.
- Mac
- Press Option+N, then a.
- Linux
- In GNOME, or any desktop running IBus, press Ctrl+Shift+U, type e3, then Space. With a Compose key set up, press Compose, tilde, a.
- Phone
- Long-press a and pick ã.
How to Type It
- Windows
- Hold Alt and type 227 on the numeric keypad, with no leading zero. US PCs insert π, but PCs set to code page 850, common in Western Europe, insert Ò. No numeric keypad? In Word, type 03C0 and press Alt+X.
- Mac
- Press Option+P.
- Linux
- In GNOME, or any desktop running IBus, press Ctrl+Shift+U, type 3c0, then Space.
- Phone
- Add the Greek keyboard in your phone's keyboard settings and type π there, or tap the character at the top of this page to copy it.
Frequently Asked Questions
utf8_encode() assumes its input is ISO-8859-1, so running it on text that's already UTF-8 encodes ã a second time and leaves não. Remove the call rather than adding a decode after it. The function is deprecated since PHP 8.2 anyway, and when you really do need to convert Latin-1, `mb_convert_encoding($s, 'UTF-8', 'ISO-8859-1')` states both encodings.
It marks a nasal vowel, the sound that separates não from a plain nao. Leaving it off can change the word entirely: manhã is morning, while manha means a tantrum or a trick. Portuguese spelling treats the tilde as required, so text without it is misspelled rather than informal.
Frequently Asked Questions
The file is UTF-8 and your editor opened it as Windows-1252, so π's two bytes appear as Ï and €. In Notepad++, choose Encoding > Encode in UTF-8, which reinterprets the bytes. Don't pick Convert to UTF-8 at that point, because it would save the garbled Ï€ as real characters.
Excel reads π as an unknown name, not a number. Use the PI() function instead: =2*PI()*A1. PI() returns the constant to 15 significant digits, which is as far as Excel's precision goes anyway. The symbol itself is fine in labels and headers, just not inside the math.