GO语言入门

练习fmt方法

package main

import (
	"fmt"
	"math"
	"strings"
)

const (
	name = "王龙"
	age  = 18
	isOK = true
)

var (
	name1 string
	age1  int
	isOK1 bool
)

func main() {

	name1 = "王龙1"
	age1 = 19
	isOK1 = true

	fmt.Println(name)
	fmt.Println(age)
	fmt.Println(isOK)
	fmt.Println(name1)
	fmt.Println(age1)
	fmt.Println(isOK1)

	fmt.Printf("%f
", math.Pi)
	fmt.Printf("%.2f
", math.Pi)

	s1 := "hello"
	s2 := "你好"
	fmt.Printf("%s
", s1)
	fmt.Printf("%s
", s2)

	s4 := "hello中国"
	for i := 0; i < len(s4); i++ {
		fmt.Printf("%v(%c)",s4[i],s4[i])
	}

	b1 :=true
	var b2 bool
	fmt.Printf("%T
",b1)
	fmt.Printf("%T value:%v
",b2,b2)

	path := "/Users/ianthony/Desktop/anthonyProject"
	fmt.Printf("%s
",path)

	s3 := `第一
第二
第三`
	fmt.Printf("%s",s3)


	name := "理想"
	world := "北京"

	// 字符串拼接
	ss := name + world
	fmt.Println(ss)

	// 字符串拼接
	ss1 := fmt.Sprintf("%s%s",name,world)
	fmt.Println(ss1)

	// 字符串拼接
	ret := strings.Split(path,"/")
	fmt.Println(ret)

	// 判断是否包含
	fmt.Println(strings.Contains(path,"ianthony"))

	// 判断是否以/开头
	fmt.Println(strings.HasPrefix(path,"/"))
	// 判断是否以t结尾
	fmt.Println(strings.HasSuffix(path,"t"))

	// 判断j的索引值是多少
	s5 := "abcdefj"
	fmt.Println(strings.Index(s5,"j"))
	// 拼接
	fmt.Println(strings.Join(ret,"/"))
	fmt.Println(strings.Join(ret,"+"))
  
  // 遍历字符串
	s := "hello沙河"
	for i := 0; i < len(s); i++ { //byte
		fmt.Printf("%c ", s[i])
	}
	fmt.Println()
	for _, r := range s { //rune
		fmt.Printf("%c ", r)
	}
	fmt.Println()
	
  // 数据类型强制转换
	n := 10
	var f float64
	f = float64(n)
	fmt.Println(f)
}