Check Element Exists in a Slice

· 237 words · 2 minutes read
#find #slice #map #element #generics #key #index #item #contains

Go doesn’t have a find or in_array function as part of it’s standard library. They are easy to create however. In this example we create a Find() function to search a slice of strings for the element we are looking for.

Cue the “generics” rant from some coders. This is a great example of why they could be useful. We have created our find function, but it only works with strings and you will have to create different find functions for different types - as needed.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34

package main

import (
    "fmt"
)

func main() {

    items := []string{"A", "1", "B", "2", "C", "3"}

    // Missing Example
    _, found := Find(items, "golangcode.com")
    if !found {
        fmt.Println("Value not found in slice")
    }

    // Found example
    k, found := Find(items, "B")
    if !found {
        fmt.Println("Value not found in slice")
    }
    fmt.Printf("B found at key: %d\n", k)
}

// Find takes a slice and looks for an element in it. If found it will
// return it's key, otherwise it will return -1 and a bool of false.
func Find(slice []string, val string) (int, bool) {
    for i, item := range slice {
        if item == val {
            return i, true
        }
    }
    return -1, false
}

check slice element

Related Posts

Image of Author Edd Turtle

Author:  Edd Turtle

Edd is the Lead Developer at Hoowla, a prop-tech startup, where he spends much of his time working on production-ready Go and PHP code. He loves coding, but also enjoys cycling and camping in his spare time.

See something which isn't right? You can contribute to this page on GitHub or just let us know in the comments below - Thanks for reading!