How to Find Length of String in Go: Simple Guide

In Go, you find the length of a string using the len() function. It returns the number of bytes in the string, which is the string's length in bytes, not necessarily the number of characters.

Syntax

The syntax to find the length of a string in Go is simple:

• len(s): where s is your string variable.
• This returns an integer representing the number of bytes in the string.

go

len(s)

Example

This example shows how to use len() to get the length of a string and print it.

go

package main

import (
	"fmt"
)

func main() {
	s := "Hello, Go!"
	length := len(s)
	fmt.Println("Length of string:", length)
}

Output

Length of string: 10

Common Pitfalls

One common mistake is assuming len() returns the number of characters. It actually returns the number of bytes. For strings with special or non-ASCII characters, this can be different.

For example, emojis or accented letters use more than one byte each.

To count characters (runes), you need to convert the string to a rune slice.

go

package main

import (
	"fmt"
)

func main() {
	s := "Go ❤️"
	fmt.Println("Byte length:", len(s)) // counts bytes
	fmt.Println("Character count:", len([]rune(s))) // counts characters
}

Output

Byte length: 6
Character count: 4

Quick Reference

Function	Description
len(s)	Returns the number of bytes in string s
len([]rune(s))	Returns the number of characters (runes) in string s

Key Takeaways

Use len(s) to get the byte length of a string in Go.

len() counts bytes, not characters, so multi-byte characters affect the count.

Convert string to []rune to count actual characters.

Remember that len() returns an integer representing length in bytes.

For simple ASCII strings, len() matches character count.