Go: Append if unique

Question

Is there a way to check slices/maps for the presence of a value?

I would like to add a value to a slice only if it does not

Answer 1

distincting a array of a struct :

func distinctObjects(objs []ObjectType) (distinctedObjs [] ObjectType){
        var output []ObjectType
    for i:= range objs{
        if output==nil || len(output)==0{
            output=append(output,objs[i])
        } else {
            founded:=false
            for j:= range output{
                    if output[j].fieldname1==objs[i].fieldname1 && output[j].fieldname2==objs[i].fieldname2 &&......... {
                    founded=true
                }
            }
            if !founded{
                output=append(output,objs[i])
            }
        }
    }
    return output
}

where the struct here is something like :

type ObjectType struct {
    fieldname1 string
    fieldname2 string
    .........
}

the object will distinct by checked fields here :

if output[j].fieldname1==objs[i].fieldname1 && output[j].fieldname2==objs[i].fieldname2 &&......... {