Go随机数实例

作者：--    发布时间：2019-11-20

go的math/rand包提供伪随机数生成。例如，rand.intn返回一个随机int n，0 <= n <100。

rand.float64返回一个float64 f，0.0 <= f <1.0。这可以用于生成其他范围内的随机浮点，例如5.0 <= f'<10.0。

可参考示例中的代码 -

所有的示例代码，都放在 f:\worksp\golang 目录下。安装go编程环境请参考：http://www.h3.com/go/go_environment.html

json.go的完整代码如下所示 -

package main

import "fmt"
import "time"

func main() {
    p := fmt.println

    // here's a basic example of formatting a time
    // according to rfc3339, using the corresponding layout
    // constant.
    t := time.now()
    p(t.format(time.rfc3339))

    // time parsing uses the same layout values as `format`.
    t1, e := time.parse(
        time.rfc3339,
        "2012-11-01t22:08:41+00:00")
    p(t1)

    // `format` and `parse` use example-based layouts. usually
    // you'll use a constant from `time` for these layouts, but
    // you can also supply custom layouts. layouts must use the
    // reference time `mon jan 2 15:04:05 mst 2006` to show the
    // pattern with which to format/parse a given time/string.
    // the example time must be exactly as shown: the year 2006,
    // 15 for the hour, monday for the day of the week, etc.
    p(t.format("3:04pm"))
    p(t.format("mon jan _2 15:04:05 2006"))
    p(t.format("2006-01-02t15:04:05.999999-07:00"))
    form := "3 04 pm"
    t2, e := time.parse(form, "8 41 pm")
    p(t2)

    // for purely numeric representations you can also
    // use standard string formatting with the extracted
    // components of the time value.
    fmt.printf("%d-%02d-%02dt%02d:%02d:%02d-00:00\n",
        t.year(), t.month(), t.day(),
        t.hour(), t.minute(), t.second())

    // `parse` will return an error on malformed input
    // explaining the parsing problem.
    ansic := "mon jan _2 15:04:05 2006"
    _, e = time.parse(ansic, "8:41pm")
    p(e)
}

执行上面代码，将得到以下输出结果 -

f:\worksp\golang>go run random-numbers.go
81,87
0.6645600532184904
7.1885709359349015,7.123187485356329
54,68
5,87
5,87

以下是纠正/补充内容：