Slices, Contains

Suppose we have a slice in our Go program, and it can have any type of elements—strings, ints, uints. We can use the slices module and its Contains method to search it.

Instead of writing a for-range loop for every single slice type, we can just use the slices module. This can reduce the size of code, making it easier to read and review.

Example

This program creates 3 different types of slices, and uses the methods from the "slices" module on them. It uses Contains, Index, and ContainsFunc.

package main

import (
    "fmt"
    "slices"
)

func main() {
    // Part 1: use Contains on a slice of strings, and with both existing and non-existing argument.
    slice := []string{"bird", "frog", "dog"}
    result := slices.Contains(slice, "frog")
    fmt.Println("Contains frog:", result)
    fmt.Println("Contains ?:", slices.Contains(slice, "?"))

    // Part 2: use Index on int slice.
    slice2 := []int{10, 20, 30}
    result2 := slices.Index(slice2, 20)
    fmt.Println("Index 20:", result2)
    fmt.Println("Index 10000:", slices.Index(slice2, 1000))

    // Part 3: use ContainsFunc on a uint slice with a lambda function argument.
    slice3 := []uint{10, 20, 30}
    result3 := slices.ContainsFunc(slice3, func(value uint) bool {
        return value >= 30
    })
    fmt.Println("ContainsFunc:", result3)
}
Contains frog: true
Contains ?: false
Index 20: 1
Index 10000: -1
ContainsFunc: true

The slices package allows us to use convenient, tested methods to search and even manipulate slices. These methods are similar in concept to the strings.Index and Contains funcs.