First, the integer type
Divided according to the length: int8, int16, int32, int64
Corresponding unsigned integer: uint8, uint16, uint32, uint64
Acquiring an object with length len ()
Ary
Decimal:
var int a = 10
fmt.Printf("%d \n",a) //10
fmt.Printf ( "% b \ n", a) // 1010% b denotes a binary placeholder
Octal:
var b = 077 you
fmt,Printf("%o \n",c) //ff
Hex:
where c int = OxFF
fmt.Printf("%x \n",c) //ff
fmt.Printf("%X \n",c) //FF
Memory Address:
fmt.Printf ( "% p \ n", & a) // 0x00004c080 placeholder% p represents hexadecimal memory address
Note: You can not convert between different type int addition and subtraction, it must be converted to the same type
any type of interface can be converted
func test() {
var a interface{} //{}表示空的interface
var b int = 100
var c float32 = 1.2
var d string = "hello"
a = b
fmt.Println("a=", a) //100
a = c
fmt.Println("a=", a) //1.2
a = d
fmt.Println("a=", a) //hello
}
Second, the float
Type: float32 float64 and is not defined by default 0 imprecise floating point, or may be the first 100 * 1000 * integer programming floating calculates output placeholder% f
Third, the Boolean type
Type: True and Flase go Flase default language can not be coerced into an integer boolean Boolean values can not be involved in operations, can not be converted to other types of formatting expressed by% t
Four, String type
Definition: internal implementations appears to utf-8 native data types
A string that represents:
"" // output will double quotes significance escapes
· // meaning of anti-quotation marks ignore escapes
Common escape character string:
\ R & lt: carriage return (return line header) \ n-: newline (skip to the next line in the same column) \ T: Tab \ ": single quote \": double quotation marks \: backslash
String common method
+或fmt.Sprintf //拼接字符串
(1)
c = c+c
fmt.Printf("c = %s\n",c)
(2)
c = fmt.Sprintf("%s%s",c,c)
fmt.Printf("c=%s\n",c)
strings.Split //分割
import "strings"
func test(){
ip := "10.10.10.1;192.168.1.1"
ipArray := strings.Split(ip,";")
fmt.Printf("first ip :%s\n",ipArray[0])
fmt.Printf("second ip :%s\n",ipArray[1])
}
strings.contains //判断是否包含
import "strings"
func test(){
ip := "10.10.10.1;192.168.1.1"
result := strings.Contains(ip,"10.10.10.1")
fmt.Println (result) // returns a Boolean value
FUNC Test () {
Import "strings"
}
strings.HasPrefix / HasSuffix // prefix and suffix Analyzing
str := "https://www.baidu.com"
if strings.HasPrefix(str,"http"){
fmt.Println("str is http url")
}else{
fmt.Println("str is not http url")
}
var last bool
last = strings.HasSuffix(str,"com")
fmt.Printf(last) //返回bool
}
strings.Index()/LastIndex() //子串出现的位置
import "strings"
func test(){
str := "https://www.baidu.com"
index := strings.Index(str,"baidu") //baidu第一次出现的位置
fmt.Printf("str is index:%d\n",index)
index = strings.LastIndex(str,"baidu") // last to appear baidu
}
fmt.Printf ( "Last baidu index:% D \ n-", index)
strings.Join (a [] string, sep string) // join operation, each element of the array according to a delimiter character string as a reference reconstitute
FUNC Test () {
var strArr [] = String [] {String "10.10. 10.1 "," 11.11.11.2 "," 12.12.12.3 "}
ResultStr = strings.Join (strArr,"; ")
fmt.Printf (" Result =% S \ n-"mresultStr) // output result = 10.10.10.1; 11.11.11.2; 12.12.12.3
}
Fifth, the character type
Definition: elements called character string, characters '' represents, there uint8 (byte) type, respectively, representing a character ASCII code; Rune type, representative of a UTF-8 character
main Package
Import "FMT"
FUNC main () {
S1: = "golang"
C1: = 'G'
fmt.Println (S1, C1) // encoding Golang 71 characters
s2: = "Chinese"
C2: = 'in' @ 3 represents characters
fmt.Println (s2, c2) // China 20013
S3: = "Go language"
fmt.Println (len (S3)). 11 // a 1-byte characters, Chinese 3 bytes
for i: = 0; i <len (s3 ); i ++ {// bytes Chinese distortion
fmt.Printf ( "% c \ n" , s3 [i]) //% c print characters
}
for K, V: Range = {S3 / / Chinese characters can be printed
fmt.Printf ( "% d,% c \ n", v) // k indicates the index number of bytes
}
}
And cast utf-8 string
main FUNC () {
S1: = "Big"
bytes 1: = [] byte (S1) // will force the string into a byte array type
fmt.Println (bytes1) // [98 105 103] , respectively, corresponding to the respective character
bytes 1 [0] = 'P'
fmt.Println (string (bytes 1)) // [112 105 103]
S1 = string (bytes 1) // byte array into a string type cast
fmt.Println (S1)
S2 : = "cabbage"
runes2: = [] Rune (S2)
runes2 [0] = 'small'
fmt.Println (String (runes2), len (runes2))
}
// only casts, can not re-assignment
String inversion operation
//英文
func main(){
s1 := "hello"
byteArray := []byte(s1) //[h e l l o]
//方法1
s2 := ""
for i :=len(byteArray)-1;i>=0;i--{
s2 = s2 + string(byteArray[i]) //byteArray[i] --> o l l e h
}
fmt.Println(s2)
//方法2
for i := 0;i<len(byteArray)/2;i++{
byteArray[i],byteArray(len(byteArray)-1-i) = byteArray(length-1-i),byteArray[i]
}
fmt.Println(string(byteArray))
}
//中文
func main(){
str := "中文"
r []rune := []rune(str)
for i := 0;i<len(r)/2;i ++ {
s [i] = tmp
tmp := r[len(str)-i-1]
r [len (str) -i-1] = s [i]
}
fmt.Println (string (r [i]))
}
Six Pointer
Seven, Array Array
Eight, Slic sliced
Nine, Map hash table
Ten, Struct structure
XI Time and Date
Using the time packet type is used to represent time time.Time
Get the current time:
now: = time.Now () to get the current time
now := time.Now().Day()
now := time.Now().Minute()
now := time.Now().Month()
now := time.Now().Year()
format:
func main(){
now := time.Now()
fmt.Printf("current time:$v\n",now)
tear := now.Year()
month := now.Month()
day := now.Day()
hour := now.Hour()
minute := now.Minute()
send := now.Second()
fmt.Printf("%02d-%02d-%02d-%02d-%02d-%02d", year, month, day, hour, minute, send)
}
Timer
main FUNC () {
TICKER: time.Tick = (. 5 * time.Second) // each 5s wherein the function performed once
for I: = {Range TICKER
fmt.Printf ( "% V \ n-", I)
function ()
}
}
format
main FUNC () {
now: = Time.now ()
fmt.Println (now.Format ( "02/1/2006 15:04"))
fmt.Println (now.Format ( "2006/1/02 15:04 "))
fmt.Println (now.Format (" 2006/1/02 "))
}
// format can be changed, time must be 2,006,102 15:04
Calculation program running time
func main(){
start := time.Now().UnixNano()
for i := 0;i<10;i++{
time.Sleep(time.Millisecond)
}
end := time.Now().UnixNano()
cost := (end - start)/1000000 //微秒化成秒
fmt.Printf("%vn",cost)
}