How to convert an int to a string type in Go


Using strconv.Itoa Function

The code snippet below shows how to convert an int to a string using the Itoa function.

package main

import (

func main() {

  s := strconv.Itoa(100)
  fmt.Printf("%q\n", s)
Warning: If we use plain int to string conversion, the integer value is interpreted as a Unicode code point. And the resulting string will contain the character represented by the code point, encoded in UTF-8.
// conversion from untyped int to string yields a string of one rune, not a string of digits (did you mean fmt.Sprint(x)?)

s := string(100) // "d"

Using strconv.FormatInt Function

FormatInt returns the string representation of i in the given base, for 2 <= base <= 36. The result uses the lower-case letters 'a' to 'z' for digit values >= 10.

Converting int64 to string. For example,

package main

import (

func main() {

  var n int64 = 108
  // Decimal
  s := strconv.FormatInt(n, 10)
  fmt.Printf("%q\n", s)

  // Binary
  s = strconv.FormatInt(n, 2)
  fmt.Printf("%q\n", s)

  // Hexadecimal
  s = strconv.FormatInt(n, 16) // "6c"
  fmt.Printf("%q\n", s)

Using fmt.Sprintf Function

The fmt.Sprintf function is a useful general tool for converting data to string:

package main

import (

func main() {

  var n int64 = 14

  s := fmt.Sprintf("%03d", n)
  fmt.Printf("%q\n", s)

The verbs

Go offers several printing “verbs” designed to format general Go values.

The verbs:
the value in a default format when printing structs, the plus flag (%+v) adds field names
a Go-syntax representation of the value
a Go-syntax representation of the type of the value
a literal percent sign; consumes no value
the word true or false
base 2
the character represented by the corresponding Unicode code point
base 10
base 8
base 8 with 0o prefix
a single-quoted character literal safely escaped with Go syntax.
base 16, with lower-case letters for a-f
base 16, with upper-case letters for A-F
Unicode format: U+1234; same as "U+%04X"
decimalless scientific notation with exponent a power of two, in the manner of strconv.FormatFloat with the 'b' format, e.g. -123456p-78
scientific notation, e.g. -1.234456e+78
scientific notation, e.g. -1.234456E+78
decimal point but no exponent, e.g. 123.456
synonym for %f
%g %e
for large exponents, %f otherwise. Precision is discussed below.
%G %E
for large exponents, %F otherwise
hexadecimal notation (with decimal power of two exponent), e.g. -0x1.23abcp+20
upper-case hexadecimal notation, e.g. -0X1.23ABCP+20
the uninterpreted bytes of the string or slice
a double-quoted string safely escaped with Go syntax
base 16, lower-case, two characters per byte
base 16, upper-case, two characters per byte
default width, default precision
width 9, default precision
default width, precision 2
width 9, precision 2
width 9, precision 0
always print a sign for numeric values; guarantee ASCII-only output for %q (%+q)
pad with spaces on the right rather than the left (left-justify the field)
alternate format: add leading 0b for binary (%#b), 0 for octal (%#o), 0x or 0X for hex (%#x or %#X); suppress 0x for %p (%#p); for %q, print a raw (backquoted) string if strconv.CanBackquote returns true; always print a decimal point for %e, %E, %f, %F, %g and %G; do not remove trailing zeros for %g and %G; write e.g. U+0078 'x' if the character is printable for %U (%#U).
' '
(space) leave a space for elided sign in numbers (% d); put spaces between bytes printing strings or slices in hex (% x, % X)
pad with leading zeros rather than spaces; for numbers, this moves the padding after the sign

Related Tags

#convert# #int# #int64#