Go can be used fmt.Sprintf to format the string in the following format:
fmt.Sprintf(Format style, parameter list…) Format style: in the form of a string, formatting symbols to
%at the beginning%sstring format,%ddecimal integer format.Parameter list: multiple parameters are separated by commas, and the number must correspond to the number in the formatting style one by one, otherwise the runtime will report an error.
2.5.1. Example #
package main import ( "fmt" "io" "os" ) func main() { // Format the string in go and assign it to a new string, using fmt.Sprintf // %S represents a string var stockcode="000987" var enddate="2020-12-31" var url="Code=%s&endDate=%s" var target_url=fmt.Sprintf(url,stockcode,enddate) fmt.Println(target_url) // Another instance,% d represents an integer const name, age = "Kim", 22 s := fmt.Sprintf("%s is %d years old.\\n", name, age) io.WriteString(os.Stdout, s) // For simplicity, ignore some errors } The output is as follows:
Code=000987&endDate=2020-12-31 Kim is 22 years old. Go string formatting symbol:
Format | Description |
|---|---|
%v | Output by the original value of the value |
%+v | Expand the structure field name and value on the basis of%v |
%#v | Output values in Go language syntax format |
%T | Output the types and values of the Go language syntax format |
%% | Output% ontology |
%b | The integer is displayed in binary mode |
%o | Integers are displayed in octal mode |
%d | Integers are displayed in decimal mode |
%x | The integer is displayed in hexadecimal mode |
%X | Integers are displayed in hexadecimal, uppercase letters |
%U | Unicode character |
%f | Floating point number |
%p | Pointer, displayed in hexadecimal mode |
2.5.2. Example #
package main import ( "fmt" "os" ) type point struct { x, y int } func main() { p := point{1, 2} fmt.Printf("%v\\n", p) fmt.Printf("%+v\\n", p) fmt.Printf("%#v\\n", p) fmt.Printf("%T\\n", p) fmt.Printf("%t\\n", true) fmt.Printf("%d\\n", 123) fmt.Printf("%b\\n", 14) fmt.Printf("%c\\n", 33) fmt.Printf("%x\\n", 456) fmt.Printf("%f\\n", 78.9) fmt.Printf("%e\\n", 123400000.0) fmt.Printf("%E\\n", 123400000.0) fmt.Printf("%s\\n", "\\"string\\"") fmt.Printf("%q\\n", "\\"string\\"") fmt.Printf("%x\\n", "hex this") fmt.Printf("%p\\n", &p) fmt.Printf("|%6d|%6d\|\\n", 12, 345) fmt.Printf("|%6.2f|%6.2f\|\\n", 1.2, 3.45) fmt.Printf("|%-6.2f|%-6.2f\|\\n", 1.2, 3.45) fmt.Printf("|%6s|%6s\|\\n", "foo", "b") fmt.Printf("|%-6s|%-6s\|\\n", "foo", "b") s := fmt.Sprintf("a %s", "string") fmt.Println(s) fmt.Fprintf(os.Stderr, "an %s\\n", "error") } The output is as follows:
{1 2} {x:1 y:2} main.point{x:1, y:2} main.point true 123 1110 ! 1c8 78.900000 1.234000e+08 1.234000E+08 "string" "\"string\"" 6865782074686973 0xc0000b4010 | 12| 345| | 1.20| 3.45| |1.20 |3.45 | | foo| b| |foo |b | a string an error