Runes

rune is an alias for int32 — they are the same type. A rune represents a single Unicode code point, which covers the full Unicode range of ~1.1 million characters. This includes ASCII characters, accented letters, emoji, CJK characters, and everything else Unicode defines.

Declaring Runes

var r1 rune = 'A'  // ASCII character — code point 65
var r2 rune = '😊' // Unicode emoji — code point 128522

Output:

Rune r1: 65     | type: int32
Rune r2: 128522 | type: int32

reflect.TypeOf() reports int32, not rune — because they are the same underlying type.

Printing as a Character

Use the %c format verb to display the character a rune represents:

fmt.Printf("r1 as character: %c\n", r1) // A
fmt.Printf("r2 as character: %c\n", r2) // 😊

Rune vs Byte

	byte (uint8)	rune (int32)
Size	8 bit	32 bit
Range	0–255	0–1,114,111
Covers	ASCII (128 chars) + extended ASCII	Full Unicode (~1.1M code points)
Literal syntax	'A'	'A', '😊'
Use case	Raw binary data, ASCII text	Unicode text, string iteration

Rune Literals Use Single Quotes

Rune literals (and byte literals) use single quotes. String literals use double quotes — these are different types:

r := 'A'   // rune (int32) — value 65
s := "A"   // string — a one-character UTF-8 string

Key Takeaways

• rune is int32: they are interchangeable — reflect.TypeOf() always shows int32
• Unicode code point: a rune holds one Unicode code point, not one byte
• Single quotes: rune literals use single quotes ('A'); string literals use double quotes ("A")
• %c format verb: prints the character represented by the rune's numeric value
• Prefer runes for Unicode text: when iterating over a string character by character, range yields (byteIndex, rune) pairs — see Loops

Related Topics

• Bytes — byte (uint8) for ASCII and raw binary data
• Strings — strings are sequences of UTF-8 bytes; range over a string yields runes
• Loops — range over a string iterates runes, not bytes
• Go Types — other built-in types