53 lines
1011 B
Go
53 lines
1011 B
Go
package main
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import (
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"fmt"
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"strconv"
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"strings"
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)
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func main() {
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var f32 float32 = 2.2
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var f64 float64 = 10.2345
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fmt.Println("f32 is", f32, ", f64 is", f64)
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var bf bool = false
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var bt bool = true
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fmt.Println("bf is", bf, ", bt is", bt)
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var s1 string = "Hello"
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var s2 string = "世界"
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fmt.Println("s1 is", s1, ", s2 is", s2)
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fmt.Println("s1+s2=", s1+s2)
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// 零值
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var zi int
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var zf float64
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var zb bool
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var zs string
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fmt.Println("zi is", zi, ", zf is", zf, "zb is", zb, ", zs is", zs)
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i := 3.14
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pi := &i
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fmt.Println(*pi)
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// 常量iota
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const (
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one = iota + 1
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two
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three
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four
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)
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fmt.Println(one, two, three, four)
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// string
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j := 5
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i2s := strconv.Itoa(j)
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s2i, err := strconv.Atoi(i2s)
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fmt.Println(i2s, s2i, err)
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f2s := strconv.FormatFloat(f64, 'e', -1, 32)
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fmt.Println(f2s)
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// 判断字符串开头是否为“H”
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fmt.Println(strings.HasPrefix(f2s, "H"))
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// 查找字符串
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fmt.Println(strings.Index(f2s, "e"))
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// 全部转大写
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fmt.Println(strings.ToUpper(f2s))
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}
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