是否有惯用的方式对golang片进行“插入” [重复]

Question

This question already has an answer here:

• Is there a way to write generic code to find out whether a slice contains specific element in Go? 4 answers

I would like to check if a value is in a slice of values. What is the best way to achieve this? Something like the following:

if "foo" in []string{"foo", "bar"}...

I've written the following code but not sure how idiomatic it is (golang newbie):

// Convert a slice or array of a specific type to array of interface{}
func ToIntf(s interface{}) []interface{} {
    v := reflect.ValueOf(s)
    // There is no need to check, we want to panic if it's not slice or array
    intf := make([]interface{}, v.Len())
    for i := 0; i < v.Len(); i++ {
        intf[i] = v.Index(i).Interface()
    }
    return intf
}
func In(s []interface{}, val interface{}) bool {
    for _, v := range s {
        if v == val {
            return true
        }
    }
    return false
}

So, to use this, here is a test method I wrote.

func TestIn(t *testing.T) {
    s := []string{"foo", "bar", "kuku", "kiki"}
    for _, v := range s {
        if !In(ToIntf(s), v) {
            t.Error("Should be in")
        }
    }
    if In(ToIntf(s), "foobar") {
        t.Error("Should not be in")
    }
}

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Answer 1

The idiomatic way, in go, for functions that can be expressed with a simple loop, to be implemented that way. Your method, for example, could be written that way:

for _, value := range slice {
    if value == var {
        doSomething()
    }
}

Obviously, it is somewhat more verbose, but that only if you try to translate language or choice here in go.

The downside of doing reflection is that you botch performances without being that simpler than if you write your code to integrate to the search rather than simply considering it a condition.