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Array Length with `len`

Part of the Fundamentals section of Coddy's GO journey — lesson 71 of 109.

The len() function returns the length (number of elements) of an array.

Create an array of colors:

colors := [4]string{"Red", "Blue", "Green", "Yellow"}

Get the array length using len():

arrayLength := len(colors)
fmt.Println("The array has", arrayLength, "elements")

This displays:

The array has 4 elements

Challenge

Beginner

In this challenge, you'll practice using the len() function to find the length of an array.

We've provided an array of favorite fruits. Your task is to find the length of this array using the len() function and store it in the numberOfFruits variable.

Cheat sheet

The len() function returns the length (number of elements) of an array:

colors := [4]string{"Red", "Blue", "Green", "Yellow"}
arrayLength := len(colors)
fmt.Println("The array has", arrayLength, "elements")

Output:

The array has 4 elements

Try it yourself

package main

import "fmt"

func main() {
	// This is our array of favorite fruits
	favoriteFruits := [5]string{"Apple", "Banana", "Orange", "Mango", "Strawberry"}
	
	// TODO: Use the len() function to find the length of the favoriteFruits array
	// and store it in the numberOfFruits variable
	var numberOfFruits int
	
	// This will print the number of fruits in the array
	fmt.Printf("There are %d fruits in the array\n", numberOfFruits)
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Fundamentals

1Introduction to Go

What is Go?Hello World Println Go Comments

4Comparison & Logical Operators

Comparison Operators - Part 1 Comparison Operators - Part 2 Logical AND Operator Logical OR Operator Logical NOT Operator Operator Precedence Basics Recap - Making Comparisons

7Control Flow: Loops

What The `for` Loop Explained For Loop - Basic For Loop - Condition Only The `break` Keyword The `continue` Keyword Nested Loops Recap - Repeating Actions

10Composite Types: Arrays

Introduction to Arrays Declaring Arrays Initializing Arrays Accessing Array ElementsArray Length with `len`Iterating Over Arrays Multi-dimensional Arrays

13Composite Types: Structs

Defining Custom Types Creating Struct Instances Accessing Struct Fields Pointers to Structs Initializing Structs Embedded Structs Anonymous Structs Recap - Custom Data Structures

2Variables and Basic Data Types

What is a variable Type Inference with `:=`Integers (int)Floating-Point Numbers Booleans Strings Zero Values Constants Naming Conventions Recap - Variables and Types

5Basic Input/Output

Formatted Output Format Verbs Printing Types Getting Basic User Input Recap - Input and Output

8Functions

Understanding Functions Declaring a Function Calling Functions Function Parameters Returning a Single Value Returning Multiple Values Named Return Values Function Scope Basics Recap - Creating Reusable Code

11Composite Types: Slices

Introduction to Slices Declaring Slice Literals Creating Slices with `make`Slice Length vs Capacity Accessing Slice Elements Appending Elements Slicing Existing Slices/Arrays Iterating Over Slices Copying Slices Recap - Dynamic Lists

14Basic Error Handling

The Concept of Errors The `error` Interface Functions Returning Errors Checking for Errors Creating Simple Errors Creating Formatted Errors Basic Error Handling Recap - Handling Problems