github.com/twelsh-aw/go/src@v0.0.0-20230516233729-a56fe86a7c81/strconv/example_test.go (about)

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package strconv_test
     6  
     7  import (
     8  	"fmt"
     9  	"log"
    10  	"strconv"
    11  )
    12  
    13  func ExampleAppendBool() {
    14  	b := []byte("bool:")
    15  	b = strconv.AppendBool(b, true)
    16  	fmt.Println(string(b))
    17  
    18  	// Output:
    19  	// bool:true
    20  }
    21  
    22  func ExampleAppendFloat() {
    23  	b32 := []byte("float32:")
    24  	b32 = strconv.AppendFloat(b32, 3.1415926535, 'E', -1, 32)
    25  	fmt.Println(string(b32))
    26  
    27  	b64 := []byte("float64:")
    28  	b64 = strconv.AppendFloat(b64, 3.1415926535, 'E', -1, 64)
    29  	fmt.Println(string(b64))
    30  
    31  	// Output:
    32  	// float32:3.1415927E+00
    33  	// float64:3.1415926535E+00
    34  }
    35  
    36  func ExampleAppendInt() {
    37  	b10 := []byte("int (base 10):")
    38  	b10 = strconv.AppendInt(b10, -42, 10)
    39  	fmt.Println(string(b10))
    40  
    41  	b16 := []byte("int (base 16):")
    42  	b16 = strconv.AppendInt(b16, -42, 16)
    43  	fmt.Println(string(b16))
    44  
    45  	// Output:
    46  	// int (base 10):-42
    47  	// int (base 16):-2a
    48  }
    49  
    50  func ExampleAppendQuote() {
    51  	b := []byte("quote:")
    52  	b = strconv.AppendQuote(b, `"Fran & Freddie's Diner"`)
    53  	fmt.Println(string(b))
    54  
    55  	// Output:
    56  	// quote:"\"Fran & Freddie's Diner\""
    57  }
    58  
    59  func ExampleAppendQuoteRune() {
    60  	b := []byte("rune:")
    61  	b = strconv.AppendQuoteRune(b, '☺')
    62  	fmt.Println(string(b))
    63  
    64  	// Output:
    65  	// rune:'☺'
    66  }
    67  
    68  func ExampleAppendQuoteRuneToASCII() {
    69  	b := []byte("rune (ascii):")
    70  	b = strconv.AppendQuoteRuneToASCII(b, '☺')
    71  	fmt.Println(string(b))
    72  
    73  	// Output:
    74  	// rune (ascii):'\u263a'
    75  }
    76  
    77  func ExampleAppendQuoteToASCII() {
    78  	b := []byte("quote (ascii):")
    79  	b = strconv.AppendQuoteToASCII(b, `"Fran & Freddie's Diner"`)
    80  	fmt.Println(string(b))
    81  
    82  	// Output:
    83  	// quote (ascii):"\"Fran & Freddie's Diner\""
    84  }
    85  
    86  func ExampleAppendUint() {
    87  	b10 := []byte("uint (base 10):")
    88  	b10 = strconv.AppendUint(b10, 42, 10)
    89  	fmt.Println(string(b10))
    90  
    91  	b16 := []byte("uint (base 16):")
    92  	b16 = strconv.AppendUint(b16, 42, 16)
    93  	fmt.Println(string(b16))
    94  
    95  	// Output:
    96  	// uint (base 10):42
    97  	// uint (base 16):2a
    98  }
    99  
   100  func ExampleAtoi() {
   101  	v := "10"
   102  	if s, err := strconv.Atoi(v); err == nil {
   103  		fmt.Printf("%T, %v", s, s)
   104  	}
   105  
   106  	// Output:
   107  	// int, 10
   108  }
   109  
   110  func ExampleCanBackquote() {
   111  	fmt.Println(strconv.CanBackquote("Fran & Freddie's Diner ☺"))
   112  	fmt.Println(strconv.CanBackquote("`can't backquote this`"))
   113  
   114  	// Output:
   115  	// true
   116  	// false
   117  }
   118  
   119  func ExampleFormatBool() {
   120  	v := true
   121  	s := strconv.FormatBool(v)
   122  	fmt.Printf("%T, %v\n", s, s)
   123  
   124  	// Output:
   125  	// string, true
   126  }
   127  
   128  func ExampleFormatFloat() {
   129  	v := 3.1415926535
   130  
   131  	s32 := strconv.FormatFloat(v, 'E', -1, 32)
   132  	fmt.Printf("%T, %v\n", s32, s32)
   133  
   134  	s64 := strconv.FormatFloat(v, 'E', -1, 64)
   135  	fmt.Printf("%T, %v\n", s64, s64)
   136  
   137  	// fmt.Println uses these arguments to print floats
   138  	fmt64 := strconv.FormatFloat(v, 'g', -1, 64)
   139  	fmt.Printf("%T, %v\n", fmt64, fmt64)
   140  
   141  	// Output:
   142  	// string, 3.1415927E+00
   143  	// string, 3.1415926535E+00
   144  	// string, 3.1415926535
   145  }
   146  
   147  func ExampleFormatInt() {
   148  	v := int64(-42)
   149  
   150  	s10 := strconv.FormatInt(v, 10)
   151  	fmt.Printf("%T, %v\n", s10, s10)
   152  
   153  	s16 := strconv.FormatInt(v, 16)
   154  	fmt.Printf("%T, %v\n", s16, s16)
   155  
   156  	// Output:
   157  	// string, -42
   158  	// string, -2a
   159  }
   160  
   161  func ExampleFormatUint() {
   162  	v := uint64(42)
   163  
   164  	s10 := strconv.FormatUint(v, 10)
   165  	fmt.Printf("%T, %v\n", s10, s10)
   166  
   167  	s16 := strconv.FormatUint(v, 16)
   168  	fmt.Printf("%T, %v\n", s16, s16)
   169  
   170  	// Output:
   171  	// string, 42
   172  	// string, 2a
   173  }
   174  
   175  func ExampleIsGraphic() {
   176  	shamrock := strconv.IsGraphic('☘')
   177  	fmt.Println(shamrock)
   178  
   179  	a := strconv.IsGraphic('a')
   180  	fmt.Println(a)
   181  
   182  	bel := strconv.IsGraphic('\007')
   183  	fmt.Println(bel)
   184  
   185  	// Output:
   186  	// true
   187  	// true
   188  	// false
   189  }
   190  
   191  func ExampleIsPrint() {
   192  	c := strconv.IsPrint('\u263a')
   193  	fmt.Println(c)
   194  
   195  	bel := strconv.IsPrint('\007')
   196  	fmt.Println(bel)
   197  
   198  	// Output:
   199  	// true
   200  	// false
   201  }
   202  
   203  func ExampleItoa() {
   204  	i := 10
   205  	s := strconv.Itoa(i)
   206  	fmt.Printf("%T, %v\n", s, s)
   207  
   208  	// Output:
   209  	// string, 10
   210  }
   211  
   212  func ExampleParseBool() {
   213  	v := "true"
   214  	if s, err := strconv.ParseBool(v); err == nil {
   215  		fmt.Printf("%T, %v\n", s, s)
   216  	}
   217  
   218  	// Output:
   219  	// bool, true
   220  }
   221  
   222  func ExampleParseFloat() {
   223  	v := "3.1415926535"
   224  	if s, err := strconv.ParseFloat(v, 32); err == nil {
   225  		fmt.Printf("%T, %v\n", s, s)
   226  	}
   227  	if s, err := strconv.ParseFloat(v, 64); err == nil {
   228  		fmt.Printf("%T, %v\n", s, s)
   229  	}
   230  	if s, err := strconv.ParseFloat("NaN", 32); err == nil {
   231  		fmt.Printf("%T, %v\n", s, s)
   232  	}
   233  	// ParseFloat is case insensitive
   234  	if s, err := strconv.ParseFloat("nan", 32); err == nil {
   235  		fmt.Printf("%T, %v\n", s, s)
   236  	}
   237  	if s, err := strconv.ParseFloat("inf", 32); err == nil {
   238  		fmt.Printf("%T, %v\n", s, s)
   239  	}
   240  	if s, err := strconv.ParseFloat("+Inf", 32); err == nil {
   241  		fmt.Printf("%T, %v\n", s, s)
   242  	}
   243  	if s, err := strconv.ParseFloat("-Inf", 32); err == nil {
   244  		fmt.Printf("%T, %v\n", s, s)
   245  	}
   246  	if s, err := strconv.ParseFloat("-0", 32); err == nil {
   247  		fmt.Printf("%T, %v\n", s, s)
   248  	}
   249  	if s, err := strconv.ParseFloat("+0", 32); err == nil {
   250  		fmt.Printf("%T, %v\n", s, s)
   251  	}
   252  
   253  	// Output:
   254  	// float64, 3.1415927410125732
   255  	// float64, 3.1415926535
   256  	// float64, NaN
   257  	// float64, NaN
   258  	// float64, +Inf
   259  	// float64, +Inf
   260  	// float64, -Inf
   261  	// float64, -0
   262  	// float64, 0
   263  }
   264  
   265  func ExampleParseInt() {
   266  	v32 := "-354634382"
   267  	if s, err := strconv.ParseInt(v32, 10, 32); err == nil {
   268  		fmt.Printf("%T, %v\n", s, s)
   269  	}
   270  	if s, err := strconv.ParseInt(v32, 16, 32); err == nil {
   271  		fmt.Printf("%T, %v\n", s, s)
   272  	}
   273  
   274  	v64 := "-3546343826724305832"
   275  	if s, err := strconv.ParseInt(v64, 10, 64); err == nil {
   276  		fmt.Printf("%T, %v\n", s, s)
   277  	}
   278  	if s, err := strconv.ParseInt(v64, 16, 64); err == nil {
   279  		fmt.Printf("%T, %v\n", s, s)
   280  	}
   281  
   282  	// Output:
   283  	// int64, -354634382
   284  	// int64, -3546343826724305832
   285  }
   286  
   287  func ExampleParseUint() {
   288  	v := "42"
   289  	if s, err := strconv.ParseUint(v, 10, 32); err == nil {
   290  		fmt.Printf("%T, %v\n", s, s)
   291  	}
   292  	if s, err := strconv.ParseUint(v, 10, 64); err == nil {
   293  		fmt.Printf("%T, %v\n", s, s)
   294  	}
   295  
   296  	// Output:
   297  	// uint64, 42
   298  	// uint64, 42
   299  }
   300  
   301  func ExampleQuote() {
   302  	// This string literal contains a tab character.
   303  	s := strconv.Quote(`"Fran & Freddie's Diner	☺"`)
   304  	fmt.Println(s)
   305  
   306  	// Output:
   307  	// "\"Fran & Freddie's Diner\t☺\""
   308  }
   309  
   310  func ExampleQuoteRune() {
   311  	s := strconv.QuoteRune('☺')
   312  	fmt.Println(s)
   313  
   314  	// Output:
   315  	// '☺'
   316  }
   317  
   318  func ExampleQuoteRuneToASCII() {
   319  	s := strconv.QuoteRuneToASCII('☺')
   320  	fmt.Println(s)
   321  
   322  	// Output:
   323  	// '\u263a'
   324  }
   325  
   326  func ExampleQuoteRuneToGraphic() {
   327  	s := strconv.QuoteRuneToGraphic('☺')
   328  	fmt.Println(s)
   329  
   330  	s = strconv.QuoteRuneToGraphic('\u263a')
   331  	fmt.Println(s)
   332  
   333  	s = strconv.QuoteRuneToGraphic('\u000a')
   334  	fmt.Println(s)
   335  
   336  	s = strconv.QuoteRuneToGraphic('	') // tab character
   337  	fmt.Println(s)
   338  
   339  	// Output:
   340  	// '☺'
   341  	// '☺'
   342  	// '\n'
   343  	// '\t'
   344  }
   345  
   346  func ExampleQuoteToASCII() {
   347  	// This string literal contains a tab character.
   348  	s := strconv.QuoteToASCII(`"Fran & Freddie's Diner	☺"`)
   349  	fmt.Println(s)
   350  
   351  	// Output:
   352  	// "\"Fran & Freddie's Diner\t\u263a\""
   353  }
   354  
   355  func ExampleQuoteToGraphic() {
   356  	s := strconv.QuoteToGraphic("☺")
   357  	fmt.Println(s)
   358  
   359  	// This string literal contains a tab character.
   360  	s = strconv.QuoteToGraphic("This is a \u263a	\u000a")
   361  	fmt.Println(s)
   362  
   363  	s = strconv.QuoteToGraphic(`" This is a ☺ \n "`)
   364  	fmt.Println(s)
   365  
   366  	// Output:
   367  	// "☺"
   368  	// "This is a ☺\t\n"
   369  	// "\" This is a ☺ \\n \""
   370  }
   371  
   372  func ExampleUnquote() {
   373  	s, err := strconv.Unquote("You can't unquote a string without quotes")
   374  	fmt.Printf("%q, %v\n", s, err)
   375  	s, err = strconv.Unquote("\"The string must be either double-quoted\"")
   376  	fmt.Printf("%q, %v\n", s, err)
   377  	s, err = strconv.Unquote("`or backquoted.`")
   378  	fmt.Printf("%q, %v\n", s, err)
   379  	s, err = strconv.Unquote("'\u263a'") // single character only allowed in single quotes
   380  	fmt.Printf("%q, %v\n", s, err)
   381  	s, err = strconv.Unquote("'\u2639\u2639'")
   382  	fmt.Printf("%q, %v\n", s, err)
   383  
   384  	// Output:
   385  	// "", invalid syntax
   386  	// "The string must be either double-quoted", <nil>
   387  	// "or backquoted.", <nil>
   388  	// "☺", <nil>
   389  	// "", invalid syntax
   390  }
   391  
   392  func ExampleUnquoteChar() {
   393  	v, mb, t, err := strconv.UnquoteChar(`\"Fran & Freddie's Diner\"`, '"')
   394  	if err != nil {
   395  		log.Fatal(err)
   396  	}
   397  
   398  	fmt.Println("value:", string(v))
   399  	fmt.Println("multibyte:", mb)
   400  	fmt.Println("tail:", t)
   401  
   402  	// Output:
   403  	// value: "
   404  	// multibyte: false
   405  	// tail: Fran & Freddie's Diner\"
   406  }
   407  
   408  func ExampleNumError() {
   409  	str := "Not a number"
   410  	if _, err := strconv.ParseFloat(str, 64); err != nil {
   411  		e := err.(*strconv.NumError)
   412  		fmt.Println("Func:", e.Func)
   413  		fmt.Println("Num:", e.Num)
   414  		fmt.Println("Err:", e.Err)
   415  		fmt.Println(err)
   416  	}
   417  
   418  	// Output:
   419  	// Func: ParseFloat
   420  	// Num: Not a number
   421  	// Err: invalid syntax
   422  	// strconv.ParseFloat: parsing "Not a number": invalid syntax
   423  }