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f462e39fa6
* 根据map章节的教程，改写String方法 * format the source code * update to make it more friendly to new learners. * Update according to comments
41 lines
688 B
Go
Executable File
41 lines
688 B
Go
Executable File
// Output:
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// Eastern Standard time
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// Universal Greenwich time
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// Central Standard time
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package main
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import "fmt"
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type TZ int
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const (
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HOUR TZ = 60 * 60
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UTC TZ = 0 * HOUR
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EST TZ = -5 * HOUR
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CST TZ = -6 * HOUR
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)
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var timeZones = map[TZ]string{
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UTC: "Universal Greenwich time",
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EST: "Eastern Standard time",
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CST: "Central Standard time"}
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func (tz TZ) String() string { // Method on TZ (not ptr)
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if zone, ok := timeZones[tz]; ok {
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return zone
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}
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return ""
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}
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func main() {
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fmt.Println(EST) // Print* knows about method String() of type TZ
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fmt.Println(0 * HOUR)
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fmt.Println(-6 * HOUR)
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}
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/* Output:
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Eastern Standard time
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Universal Greenwich time
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Central Standard time
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*/
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