格式化 I/O

通用

  1. %v    the value in a default format
  2.     when printing structs, the plus flag (%+v) adds field names
  3. %#v    a Go-syntax representation of the value
  4. %T    a Go-syntax representation of the type of the value
  5. %%    a literal percent sign; consumes no value

Boolean

  1. %t    the word true or false

Integer:

  1. %c    the character represented by the corresponding Unicode code point
  2. %d    base 10
  3. %o    base 8
  4. %O    base 8 with 0o prefix
  5. %q    a single-quoted character literal safely escaped with Go syntax.
  6. %x    base 16, with lower-case letters for a-f
  7. %X    base 16, with upper-case letters for A-F
  8. %U    Unicode format: U+1234; same as "U+%04X"

Floating-point and complex constituent

  1. %b    decimalless scientific notation with exponent a power of two,
  2.     in the manner of strconv.FormatFloat with the 'b' format,
  3.     e.g. -123456p-78
  4. %e    scientific notation, e.g. -1.234456e+78
  5. %E    scientific notation, e.g. -1.234456E+78
  6. %f    decimal point but no exponent, e.g. 123.456
  7. %F    synonym for %f
  8. %g    %e for large exponents, %f otherwise. Precision is discussed below.
  9. %G    %E for large exponents, %F otherwise
  10. %x    hexadecimal notation (with decimal power of two exponent), e.g. -0x1.23abcp+20
  11. %X    upper-case hexadecimal notation, e.g. -0X1.23ABCP+20

String and slice of bytes

  1. %s    the uninterpreted bytes of the string or slice
  2. %q    a double-quoted string safely escaped with Go syntax
  3. %x    base 16, lower-case, two characters per byte
  4. %X    base 16, upper-case, two characters per byte

Slice

  1. %p    address of 0th element in base 16 notation, with leading 0x

Pointer:

  1. %p    base 16 notation, with leading 0x
  2. The %b, %d, %o, %x and %X verbs also work with pointers,
  3. formatting the value exactly as if it were an integer.

精度

  1. %f     default width, default precision
  2. %9f    width 9, default precision
  3. %.2f   default width, precision 2
  4. %9.2f  width 9, precision 2
  5. %9.f   width 9, precision 0

其他标志

  1. +    always print a sign for numeric values;
  2.     guarantee ASCII-only output for %q (%+q)
  3. -    pad with spaces on the right rather than the left (left-justify the field)
  4. #    alternate format: add leading 0b for binary (%#b), 0 for octal (%#o),
  5.     0x or 0X for hex (%#x or %#X); suppress 0x for %p (%#p);
  6.     for %q, print a raw (backquoted) string if strconv.CanBackquote
  7.     returns true;
  8.     always print a decimal point for %e, %E, %f, %F, %g and %G;
  9.     do not remove trailing zeros for %g and %G;
  10.     write e.g. U+0078 'x' if the character is printable for %U (%#U).
  11. ' '    (space) leave a space for elided sign in numbers (% d);
  12.     put spaces between bytes printing strings or slices in hex (% x, % X)
  13. 0    pad with leading zeros rather than spaces;
  14.     for numbers, this moves the padding after the sign

输入

Scan, Scanf and Scanln read from os.Stdin; Fscan, Fscanf and Fscanln read from a specified io.Reader; Sscan, Sscanf and Sscanln read from an argument string.

方法