Golang Study-StrConv Bag

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Converts a Boolean value to a string true or Falsefunc Formatbool (b bool) string//converts a string to a Boolean value//it accepts true value: 1, T, T, Real, true, true//it accepts false values: 0, F, F, f Alse, False, false//any other value returns an error. Func parsebool (str string) (bool, error)------------------------------//Errrange indicates that the value is out of range var errrange = errors. New ("Value out of range")//Errsyntax indicates incorrect syntax var errsyntax = errors. New ("Invalid Syntax")//Converts an integer to a string form. Base represents the conversion, with a value between 2 and 36. A number greater than 10 in the result is represented by a A-Z in lowercase letters. Func Formatint (i int64, base int) Stringfunc Formatuint (i uint64, base int) string//parse string to integer, parseint support sign, parseuint unsupported Sign. Base represents the Carry system (2 to 36), if base is 0, the string prefix is judged,//prefix 0x means 16, prefix 0 is 8, otherwise 10 is the binary. The bitsize represents the bit width of the result (including the sign bit), and 0 indicates the maximum bit width. Func parseint (s string, base int, bitsize int) (I int64, err error) Func Parseuint (s string, base int, bitsize int) (UInt64 , error)//Converts an integer to a decimal string (i.e., shorthand for formatint (I, 10)) func Itoa (i int) string//converts a string to a decimal integer, namely: parseint (S, 10, 0) func Atoi (s string) (int, error)------------------------------//example Func main () {FMT. PrintlN (StrConv. parseint ("FF", 0)//255fmt. Println (StrConv. parseint ("0xFF", 0))//0 StrConv. Parseint:parsing "0xFF": Invalid SYNTAXFMT. Println (StrConv. parseint ("0xFF", 0, 0)//255fmt. Println (StrConv. parseint ("9", ten, 4))//7 StrConv. Parseint:parsing "9": Value out of range}------------------------------//formatfloat to convert floating-point number f to string form/F: floating-point number to convert//FMT: Lattice (b, E, E, F, g, g)//PREC: Precision (length of the digital part, excluding exponential portion)//bitsize: Specifies the floating-point type (32:float32, 64:float64), and the result is rounded accordingly. Format Tags://' B ' (-ddddp±ddd, binary exponent)//' E ' (-d.dddde±dd, decimal index)//' E ' (-d.dddde±dd, decimal index)//' F ' (-ddd.dddd, no exponent)//' G ' (' E ' : Large exponent, ' F ': Other conditions)//' G ' (' e ': large exponent, ' F ': other case)////if the format is marked ' E ', ' e ' and ' f ', then prec represents the number of digits after the decimal point//If the format is marked ' g ', ' g ', then Prec Represents the total number of digits (integer part + fractional part)//reference format input and output in the flag and precision description func formatfloat (f float64, FMT Byte, prec, Bitsize int) string//parses a string into a floating-point number, using I The EEE754 specification is rounded. The bigsize values are 32 and 642, indicating the precision of the conversion result. If there is a syntax error, err. Error = errsyntax//returns ±INF,ERR If the result is out of range. Error = Errrangefunc parsefloat (s string, bitsize int) (float64, error)------------------------------//Example Func main () {s: = "0.12345678901234567890" F, err: = StrConv. Parsefloat (S, +) FMT. Println (f, Err)//0.12345679104328156FMT. Println (float32 (f), err)//0.12345679f, err = StrConv. Parsefloat (S, +) FMT. Println (f, Err)//0.12345678901234568}------------------------------//Determines whether the string can be modified to represent a single line of anti-quote strings. The string cannot contain a control character (except \ t) and an "anti-quote" character, otherwise return Falsefunc Canbackquote (s string) bool//example: Find all! The Canbackquote character Func main () {for I: = Rune (0); i < UTF8. Maxrune; i++ {if!strconv. Canbackquote (String (i)) {fmt.  Printf ("%q,", i)}}}//results as follows://' \x00 ', ' \x01 ', ' \x02 ', ' \x03 ', ' \x04 ', ' \x05 ', ' \x06 ', ' \ n ', ' \a ', ' \b ', ' \ R ', ' \x0e ', ' \x0f ', ' \x10 ', ' \x11 ', ' \x12 ', ' \x13 ', ' \x14 ', ' \x15 ', ' \x16 ', ' \x17 ', ' \x18 ', ' \x19 ', ' \x1a ', ' \x1b ', ' \x1c ', ' \x1d ', ' \x1e ', ' \x1f ', ' ', ' \u007f ', ' \ufeff '------------------------------//Determine if R is a printable character//can print is not what you think, such as spaces can be printed, and \ t cannot print the Func isprint (R rune) bool//determines whether R is a Unicode-defined graphic character. Func isgraphic (R rune) BOOL------------------------------//Example: Get non-printable characters and non-graphic characters func main () {var rnp, rng, Rpng, RGNP []runeconst maxlen = 32for I : = Rune (0); I < UTF8. Maxrune; i++ {if!strconv. Isprint (i) {//non-printable If Len (RNP) < MaxLen {RNP = append (RNP, i)}if StrConv. Isgraphic (i) && len (RGNP) < MaxLen {//graphics characters RGNP = append (RGNP, i)}}if!strconv. Isgraphic (i) {//non-graphic characters if Len (RNG) < MaxLen {rng = append (rng, i)}if StrConv. Isprint (i) && len (rpng) < MaxLen {//printable Rpng = append (Rpng, i)}}}fmt. Printf ("non-printable characters:%q\n", RNP) fmt. Printf ("Non-graphic character:%q\n", rng) fmt. Printf ("non-printable graphic characters:%q\n", RGNP) fmt. Printf ("Printable non-graphic character:%q\n", rpng)}//non-printable characters: [' \x00 ' \x01 ' ' \x02 ' "\x03 ' \x04 ' \x05 ' \x06 ' \a ', '" \ r \ n ' "\b" \v " "\ r" ' \x0e ' ' \x0f ' \x10 ' \x11 ' \x12 ' \x13 ', ' and ', \x14 ', ' \x15 ' ' \x16 ', ' and ' ' \x17 ', ' \x18 ', ' and ', ', ' the ', ' and ', ' \x19 ' \x1a ' \x1b ' \x1c 1e ' \x1f ']//non-graphic characters: [' \x00 ' \x01 ' \x02 ' ' \x03 ', ' \x04 ' and ' ' \x05 ' \x06 ' \a ' ' \ R ' \b ' \ t ' \ n ' ' \v ' ' \f ' \x0e F ' \x10 ' \x11 ' \x12 ' \x13 '' \x14 ' ' \x15 ' \x16 ' \x17 ' \x18 ' \x19 ', ' \x1a ', ' \x1b ', ' \x1c ', \x1d ' \x1e ' \x1f ']//' \u00a0 ' the non-printable graphic character: [' \u1680 ' ' \u2000 ' "\u2001" \u2002 "\u2003" \u2005 "\u2006" \u2007 "\u2008" ' \u2009 ' \u200a ' "\u202f", "\u2004", "the" "the", "and the" "The" "\u205f" printable non-graphic characters: []------------------------------//convert s to double quote string func Quote (s string) string//function, non-ASCII characters and nonprinting characters are escaped func Quotetoascii (s string) string//function, non-graphic character is escaped func quotetographic (s string) string------------------------------// Example Func Main () {s: = "hello\t world!" \ n "FMT. PRINTLN (s)//Hello World! (newline) fmt. Println (StrConv. Quote (s))//"Hello\t world! \ n "FMT. Println (StrConv. Quotetoascii (s))//"hello\t\u4e16\u754c\uff01\n" FMT. Println (StrConv. Quotetographic (s))//"Hello\t world! \ n "}------------------------------//convert R to single quote character Func Quoterune (R rune) string//function, non-ASCII characters and nonprinting characters are escaped func Quoterunetoascii (R rune) string//function, non-graphic characters are escaped by Func Quoterunetographic (R rune) string------------------------------ Unquote converts "quoted string" s toA regular string (without quotation marks and escape characters)//s can be a string (including the quotation marks itself) that is caused by the "single quote", "double quotation mark", or "anti-quotation mark"//If S is a string that is enclosed in single quotation marks, then returns the character that the string represents, Func unquote (S string) ( string, error)//Unquotechar "de-escaping" the first character in the quoted string (without the end-to-end quotation marks) and decoding////s: quoted string (does not contain the end-to-end quotation marks)//quote: String used by the "quote symbol" (Used to "de-escape" the quotation marks in a string)////value: Whether the decoded character//Multibyte:value is a multibyte character//tail: The remainder of the string s decoded//error: Returns the presence of a syntax error in s  The parameter quote is "quotation mark"///if set to single quotation marks, the S is allowed to appear \ ', ' character, do not allow separate ' characters//if set to double quotation marks, s in the Allow \ ", ' character, not allowed to appear separate" character//If set to 0, it is not allowed to appear \ ' or \ ' character, but can appear separate ' or ' character func Unquotechar (s string, quote byte) (value rune, multibyte bool, tail string, err error)-- ----------------------------//Example Func main () {s1: = "' Hello World! '//Parse back quote string s2: = ' "hello\t\u4e16\u754c\uff01" '//Parse double quote string FMT. Println (StrConv. Unquote (S1))//Hello World! <nil>fmt. Println (StrConv. unquote (S2))//Hello World! <nil>fmt. Println () fmt. Println (StrConv. Unquotechar (' \u4e16\u754c\uff01 ', 0))//19990 true \u754c\uff01 <nil>fmt. Println (StrConv. Unquotechar (' \ ' abc\ "', '" ')//False abc\ "&LT;NIL&GT;}------------------------------//convert various types to strings and append to the DST trailer. Func appendint (DST []byte, I int64, base int) []bytefunc appenduint (DST []byte, I uint64, base int) []bytefunc appendfloat (DST []byte, F float64, FMT Byte, prec, Bitsize int) []bytefunc Appendbool (DST []byte, b bool) []byte//the various types are converted to quoted strings appended to the DST trailer. Func appendquote (DST []byte, S string) []bytefunc appendquotetoascii (DST []byte, S string) []bytefunc Appendquotetographi C (DST []byte, S string) []bytefunc appendquoterune (DST []byte, R rune) []bytefunc appendquoterunetoascii (DST []byte, R run e) []bytefunc appendquoterunetographic (DST []byte, R rune) [] BYTE------------------------------------------------------------