How to Find Length of Array in Go: Simple Guide

In Go, you find the length of an array using the len() function. Just pass your array variable inside len(), and it returns the number of elements in the array.

Syntax

The syntax to find the length of an array in Go is simple:

• len(arrayName): Returns the number of elements in the array.

Here, arrayName is your array variable.

go

length := len(arrayName)

Example

This example shows how to declare an array and find its length using len(). It prints the length to the console.

go

package main

import "fmt"

func main() {
    numbers := [5]int{10, 20, 30, 40, 50}
    length := len(numbers)
    fmt.Println("Length of array:", length)
}

Output

Length of array: 5

Common Pitfalls

Some common mistakes when finding array length in Go:

• Using len() on a slice works the same, but slices can change size, unlike arrays.
• Trying to get length by accessing an index like arrayName.length does not work in Go.
• Confusing arrays with slices: arrays have fixed size, slices are more flexible.

go

package main

import "fmt"

func main() {
    arr := [3]int{1, 2, 3}
    // Wrong: fmt.Println(arr.length) // This will cause a compile error
    fmt.Println(len(arr)) // Correct way
}

Output

3

Quick Reference

Remember these points when working with array length in Go:

• len(array) returns the number of elements.
• Arrays have fixed size; slices can grow or shrink.
• Use len() for both arrays and slices.

Key Takeaways

Use the built-in len() function to get the length of an array in Go.

len() works for both arrays and slices but remember arrays have fixed size.

Do not try to access length as a property like array.length; it causes errors.

Slices are more flexible than arrays but len() usage is the same.

Always pass the array variable inside len() to get its size.