【问题】
折腾:
【记录】go语言中把代码移至独立的函数中:搞懂go语言中函数的写法
期间,用如下代码:
package main import ( "fmt" "runtime" "path" "strings" ) // GetCurFilename // Get current file name, without suffix func GetCurFilename() string { _, fulleFilename, line, _ := runtime.Caller(0) //fmt.Println(fulleFilename) //fmt.Println(line) var filenameWithSuffix string filenameWithSuffix = path.Base(fulleFilename) //fmt.Println("filenameWithSuffix=", filenameWithSuffix) var fileSuffix string fileSuffix = path.Ext(filenameWithSuffix) //fmt.Println("fileSuffix=", fileSuffix) //filenameWithSuffix = "EmulateLoginBaidu" //fileSuffix = ".go" //filenameWithSuffix = "EmulateLoginBaidu.go.go.go" //fileSuffix = ".go" //filenameWithSuffix = "EmulateLoginBaidu.go.txt" //fileSuffix = ".go" var filenameOnly string filenameOnly = strings.TrimSuffix(filenameWithSuffix, fileSuffix) //fmt.Println("filenameOnly=", filenameOnly) return filenameOnly } func main() { fmt.Printf("this is EmulateLoginBaidu.go\n") var filenameOnly string filenameOnly = GetCurFilename() fmt.Println("filenameOnly=", filenameOnly) }
运行,结果出错:
D:\tmp\tmp_dev_root\go\src\github.com\user\EmulateLoginBaidu>go run EmulateLoginBaidu.go .\EmulateLoginBaidu.go:17: line declared and not used |
如图:
即:
line declared and not used |
【解决过程】
1.然后后来才注意到,原来是:
_, fulleFilename, line, _ := runtime.Caller(0) //fmt.Println(fulleFilename) //fmt.Println(line)
中的返回值line,后面没有用到,所以有此警告。
2.所以,去参考:
_, fulleFilename, line, _ := runtime.Caller(0)
的写法,推测是:
下划线_,表示忽略此返回值,所以去改为:
func GetCurFilename() string { _, fulleFilename, _, _ := runtime.Caller(0) //fmt.Println(fulleFilename)
试试结果:
然后程序就正常执行了,没有了此警告了:
D:\tmp\tmp_dev_root\go\src\github.com\user\EmulateLoginBaidu>go run EmulateLoginBaidu.go this is EmulateLoginBaidu.go filenameOnly= EmulateLoginBaidu
如图:
【总结】
go代码中,如果有变量(赋值了)但是后期没有引用,就会出现:
line declared and not used |
的警告(而导致程序无法编译过,无法运行)
转载请注明:在路上 » 【已解决】go语言运行出错:# command-line-arguments .\EmulateLoginBaidu.go:17: line declared and not used