Golang拾遗之自定义类型和方法集详解

package main
 
import (
    "encoding/json"
    "fmt"
    "time"
)
 
type MyTime time.Time
 
func main() {
    myTime := MyTime(time.Now()) // 假设获得的时间是 2022年7月20日20：30：00，时区UTC+8
    res, err := json.Marshal(myTime)
    if err != nil {
        panic(err)
    }
    fmt.Println(string(res))
}

package main
 
import (
    "fmt"
    "time"
)
 
type MyTime time.Time
 
func main() {
    myTime := MyTime(time.Now()) // 假设获得的时间是 2022年7月20日20：30：00，时区UTC+8
    res, err := myTime.MarsharlJSON()
    if err != nil {
            panic(err)
    }
    fmt.Println(string(res))
}

type Time struct {
        // wall and ext encode the wall time seconds, wall time nanoseconds,
        // and optional monotonic clock reading in nanoseconds.
        //
        // From high to low bit position, wall encodes a 1-bit flag (hasMonotonic),
        // a 33-bit seconds field, and a 30-bit wall time nanoseconds field.
        // The nanoseconds field is in the range [0, 999999999].
        // If the hasMonotonic bit is 0, then the 33-bit field must be zero
        // and the full signed 64-bit wall seconds since Jan 1 year 1 is stored in ext.
        // If the hasMonotonic bit is 1, then the 33-bit field holds a 33-bit
        // unsigned wall seconds since Jan 1 year 1885, and ext holds a
        // signed 64-bit monotonic clock reading, nanoseconds since process start.
        wall uint64
        ext  int64
 
        // loc specifies the Location that should be used to
        // determine the minute, hour, month, day, and year
        // that correspond to this Time.
        // The nil location means UTC.
        // All UTC times are represented with loc==nil, never loc==&utcLoc.
        loc *Location
}

- type MyTime time.Time
+ type MyTime = time.Time
 
func main() {
-   myTime := MyTime(time.Now()) // 假设获得的时间是 2022年7月20日20：30：00，时区UTC+8
+   var myTime MyTime = time.Now() // 假设获得的时间是 2022年7月20日20：30：00，时区UTC+8
    res, err := json.Marshal(myTime)
    if err != nil {
        panic(err)
    }
    fmt.Println(string(res))
}

- type MyTime time.Time
+ type MyTime struct {
+     time.Time
+ }
 
func main() {
-   myTime := MyTime(time.Now()) // 假设获得的时间是 2022年7月20日20：30：00，时区UTC+8
+   myTime := MyTime{time.Now}
    res, err := myTime.MarsharlJSON()
    if err != nil {
            panic(err)
    }
    fmt.Println(string(res))
}

type MyTime time.Time
 
func (m MyTime) MarshalJSON() ([]byte, error) {
    // 我图方便就直接复用Time的了
    return time.Time(m).MarshalJSON()
}
 
func main() {
    myTime := MyTime(time.Now()) // 假设获得的时间是 2022年7月20日20：30：00，时区UTC+8
    res, err := myTime.MarsharlJSON()
    if err != nil {
            panic(err)
    }
    fmt.Println(string(res))
}