Text and HTML templates / Built-in functions / Essential Go
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package main
import (
"log"
"os"
"text/template"
)
const tmplStr = `len(nil) : {{ len .SliceNil }}
len(emptySlice): {{ len .SliceEmpty }}
len(slice) : {{ len .Slice }}
len(map) : {{ len .Map }}
`
func main() {
t := template.Must(template.New("len").Parse(tmplStr))
data := struct {
SliceNil []int
SliceEmpty []string
Slice []bool
Map map[int]bool
}{
SliceNil: nil,
SliceEmpty: []string{},
Slice: []bool{true, true, false},
Map: map[int]bool{5: true, 3: false},
}
err := t.Execute(os.Stdout, data)
if err != nil {
log.Fatalf("t.Execute() failed with '%s'\n", err)
}
}
Go
INFO