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

Question

I want to know is there a generic way to write code to judge whether a slice contains an element, I find it will frequently useful since there is a lot of logic to fist judg

Answer 1

I'm not sure what your specific context is, but you'll probably want to use a map to check if something already exists.

package main

import "fmt"

type PublicClassObjectBuilderFactoryStructure struct {
    Tee string
    Hee string
}

func main() {
    // Empty structs occupy zero bytes.
    mymap := map[interface{}]struct{}{}

    one := PublicClassObjectBuilderFactoryStructure{Tee: "hi", Hee: "hey"}
    two := PublicClassObjectBuilderFactoryStructure{Tee: "hola", Hee: "oye"}

    three := PublicClassObjectBuilderFactoryStructure{Tee: "hi", Hee: "again"}

    mymap[one] = struct{}{}
    mymap[two] = struct{}{}

    // The underscore is ignoring the value, which is an empty struct.
    if _, exists := mymap[one]; exists {
        fmt.Println("one exists")
    }

    if _, exists := mymap[two]; exists {
        fmt.Println("two exists")
    }

    if _, exists := mymap[three]; exists {
        fmt.Println("three exists")
    }
}

Another advantage of using maps instead of a slice is that there is a built-in delete function for maps. https://play.golang.org/p/dmSyyryyS8