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.yiibai.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:
本實例是時間格式化那節的,應該更換。 提交时间:2019-08-22