map中的結構體元素是無法取位址的，即：map[string]struct型別，取&map["tmp"]是錯誤的。會提示報錯：
cannot assign to struct field elem["count"].count in map。package main
import (
"fmt"
"time"
)// counter 代表計數器的型別。
type counter struct
var mapchan = make(chan map[string]counter, 1)
func main() , 2)
go func() else
} fmt.println("[receiver] stopped.")
syncchan <- struct{}{} // 傳送同步通知
}()go func() ,
} for i := 0; i < 5; i++
close(mapchan)
syncchan <- struct{}{} // 傳送同步通知
}()<-syncchan //接收同步通知
<-syncchan //接收同步通知
}
[receiver] the elem is: map[count:]. elem address: 0xc000078000
[receiver] the counter: 1.
[sender] the count map: map[count:]. count map address: 0xc00000c030
[sender] the counter: 0.
[receiver] the elem is: map[count:]. elem address: 0xc000078010
[receiver] the counter: 1.
[sender] the count map: map[count:]. count map address: 0xc00000c030
[sender] the counter: 0.
[receiver] the elem is: map[count:]. elem address: 0xc0000a0000
[receiver] the counter: 1.
[sender] the count map: map[count:]. count map address: 0xc00000c030
[sender] the counter: 0.
[receiver] the elem is: map[count:]. elem address: 0xc00000c040
[receiver] the counter: 1.
[sender] the count map: map[count:]. count map address: 0xc00000c030
[sender] the counter: 0.
[receiver] the elem is: map[count:]. elem address: 0xc000078020
[receiver] the counter: 1.
[sender] the count map: map[count:]. count map address: 0xc00000c030
[sender] the counter: 0.
[receiver] stopped.
package main
import (
"fmt"
"time"
)// counter 代表計數器的型別。
type counter struct
var mapchan = make(chan map[string]*counter, 1)
func main() , 2)
go func() else
} fmt.println("[receiver] stopped.")
syncchan <- struct{}{}
}()go func() ,
} for i := 0; i < 5; i++
close(mapchan)
syncchan <- struct{}{}
}()<-syncchan
<-syncchan
}
[receiver] the elem is: map[count:0xc000074008]. elem address: 0xc00008a000
[receiver] the counter: 1.
[sender] the count map: map[count:0xc000074008]. count map address: 0xc000082020
[sender] the counter: 1.
[receiver] the elem is: map[count:0xc000074008]. elem address: 0xc00008a010
[receiver] the counter: 2.
[sender] the count map: map[count:0xc000074008]. count map address: 0xc000082020
[sender] the counter: 2.
[receiver] the elem is: map[count:0xc000074008]. elem address: 0xc00000c010
[receiver] the counter: 3.
[sender] the count map: map[count:0xc000074008]. count map address: 0xc000082020
[sender] the counter: 3.
[receiver] the elem is: map[count:0xc000074008]. elem address: 0xc00000c018
[receiver] the counter: 4.
[sender] the count map: map[count:0xc000074008]. count map address: 0xc000082020
[sender] the counter: 4.
[receiver] the elem is: map[count:0xc000074008]. elem address: 0xc00000c020
[receiver] the counter: 5.
[sender] the count map: map[count:0xc000074008]. count map address: 0xc000082020
[sender] the counter: 5.
[receiver] stopped.
package main
import (
"fmt"
"time"
)var mapchan = make(chan map[string]int, 1)
func main() , 2)
go func() else
} fmt.println("[receiver] stopped.")
syncchan <- struct{}{} // 傳送同步通知
}()go func()
close(mapchan) // 關閉通道
syncchan <- struct{}{} // 傳送同步通知
}()<-syncchan //接收同步通知
<-syncchan //接收同步通知
fmt.println(" map為引用型別，傳送和接收的元素指向同乙個值.")
}
[receiver] the elem is: map[count:2]. elem address is: 0xc000078000
[sender] the count map: map[count:2]. count map address: 0xc00000c030
[receiver] the elem is: map[count:4]. elem address is: 0xc000078010
[sender] the count map: map[count:4]. count map address: 0xc00000c030
[receiver] the elem is: map[count:6]. elem address is: 0xc00000c040
[sender] the count map: map[count:6]. count map address: 0xc00000c030
[receiver] the elem is: map[count:8]. elem address is: 0xc0000a4000
[sender] the count map: map[count:8]. count map address: 0xc00000c030
[receiver] the elem is: map[count:10]. elem address is: 0xc000078020
[sender] the count map: map[count:10]. count map address: 0xc00000c030
[receiver] stopped.
map為引用型別，傳送和接收的元素指向同乙個值.
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