go一些数据类型转换 sort、strconv包

//maxValue and minValue
math.MaxInt64
math.MinInt64
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//Sort a map by key or value
m := map[string]int{"Alice": 2, "Cecil": 1, "Bob": 3}
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keys := make([]string, 0, len(m))
for k := range m {
    keys = append(keys, k)
}
sort.Strings(keys)
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for _, k := range keys {
    fmt.Println(k, m[k])
}
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切片排序

sort.Ints([]int)
sort.Strings(string)
sort.Float64s(float64)
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//sort slice，不稳定，稳定的话用SliceStake
func Slice(x any, less func(i, j int) bool)
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func main() {
    people := []struct {
        Name string
        Age  int
    }{
        {"Gopher", 7},
        {"Alice", 55},
        {"Vera", 24},
        {"Bob", 75},
    }
    sort.Slice(people, func(i, j int) bool { return people[i].Name < people[j].Name })
    fmt.Println("By name:", people)
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    sort.Slice(people, func(i, j int) bool { return people[i].Age < people[j].Age })
    fmt.Println("By age:", people)
}

常见的类型转换

strings.Join(s1 []string, sep string)   //用sep把s1中的所有元素链接起来
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strconv.Itoa(i int)string   //把一个整数i转成字符串
strconv.Atoi(str string)int //把一个字符串转成整数   
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//parse: convert string to outher types
b, err := strconv.ParseBool("true")         // result: true, bool
f, err := strconv.ParseFloat("3.14", 64)    // result: 3.14, float64
i, err := strconv.ParseInt("-18", 10, 64)   // result:  -18, int64
u, err := strconv.ParseUint("18", 10, 64)   // result:   18, int64
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//format: convert others to string
strconv.FormatInt(123, 10)  // 123  int-->string  10表示十进制
strconv.Itoa(123)   // 123  十进制int-->string
strconv.FormatFloat(3.14, 'f', 6, 64) // 3.140000  float-->string  6:保留6位  64:float64
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