Golang golang-in array (snippet)

Go programming example 'golang-in array'

golang-in array

Golang beginners example: golang-in array

package main

import (
    "fmt"
    "reflect"
)

// InArray will search element inside array with any type.
// Will return boolean and index for matched element.
// True and index more than 0 if element is exist.
// needle is element to search, haystack is slice of value to be search.
func InArray(needle interface{}, haystack interface{}) (exists bool, index int) {
    exists = false
    index = -1

    switch reflect.TypeOf(haystack).Kind() {
    case reflect.Slice:
        s := reflect.ValueOf(haystack)

        for i := 0; i < s.Len(); i++ {
            if reflect.DeepEqual(needle, s.Index(i).Interface()) == true {
                index = i
                exists = true
                return
            }
        }
    }

    return
}

func main() {
    // Array of string
    arrStrings := []string{"foo", "bar", "baz"}
    searchString := "bar"
    stringExist, stringIndex := InArray(searchString, arrStrings)
    fmt.Printf("The '%s' is %v inside arrays %v with index: %d\n", searchString, stringExist, arrStrings, stringIndex)

    // Array of int64 (or you can use int or int32 too)
    arrInt64 := []int64{2016, 2017, 2018, 2019}
    searchInt64 := int64(2016)
    int64Exist, int64Index := InArray(searchInt64, arrInt64)
    fmt.Printf("The '%d' is %v inside arrays %v with index: %d\n", searchInt64, int64Exist, arrInt64, int64Index)

    // Example for false searching
    int64NotExist := int64(2000)
    isElementExist, foundElementIndex := InArray(int64NotExist, arrInt64)
    fmt.Printf("The '%d' is %v inside arrays %v with index: %d\n", int64NotExist, isElementExist, arrInt64, foundElementIndex)

    // False searching with different type
    // Search string inside array of int64
    searchStringInt64 := "2018"
    isStringExistInInt64Arr, stringIndexIn64ArrElement := InArray(searchStringInt64, arrInt64)
    fmt.Printf("The '%s' (%v) is %v inside arrays %v with index: %d\n", searchStringInt64, reflect.TypeOf(searchStringInt64).Name(), isStringExistInInt64Arr, arrInt64, stringIndexIn64ArrElement)

    // Or, you can also using array of interface
    arrInterface := []interface{}{"username", 123, int64(10), false}
    searchElement := false
    ok, index := InArray(searchElement, arrInterface)
    fmt.Printf("The '%v' is %v inside arrays %v with index: %d\n", searchElement, ok, arrInterface, index)
}

Useful links

• Learn Go: https://golangr.com
• Download Go: https://golang.org