package main
import (
    "fmt"
)
func Exists(myvalue int, mymap map[string]int) bool {
    for _, value := range mymap {
        if value == myvalue {
            return true
        }
    }
    return false
}
func main() {
    mymap := map[string]int{
        "Tivi":     230,
        "Laptop":   1200,
        "Mobile":   500,
        "Computer": 98,
    }
    ok := Exists(230, mymap)
    if ok {
        fmt.Println("Value Found")
    } else {
        fmt.Println("Value not found")
    }
}       
        
Output
Value Found