Multiline Strings in Go: 5 Fatal Errors and How to Avoid Them

Multiline Strings in Go: Pitfalls That Even Experienced Developers Face

Imagine this: you're writing an SQL query, a JSON template, or just a long log message in Go. You intuitively press Enter to break the line, and... the compiler throws an error. Sound familiar? The question "How do you write multiline strings in Go?" on Stack Overflow has gathered thousands of views for a reason. It's one of those small details that can stump even those who have already mastered the language's syntax.

In this article, we'll break down the top 5 fatal errors when working with multiline strings in Go and show you how to avoid them. You'll learn the difference between interpreted and raw literals, why an extra space can ruin your day, and how to format your code correctly. Let's go!

Mistake #1: Using Double Quotes for Multiline Text

The most common mistake beginners make is trying to write a multiline string inside double quotes ("). In Go, double quotes create an interpreted string literal. This means that a newline character inside them is forbidden.

// This code will NOT compilepackage main

import "fmt"

func main() {    // Error: unexpected newline in string literal    message := "Hello,    world!"    fmt.Println(message)}

The Go compiler is strict: it sees an unclosed quote and a newline character, which leads to a syntax error. Remember: double quotes are for single-line strings only.

Mistake #2: Ignoring Raw String Literals

The solution to multiline strings is raw string literals. They are created using backticks (`). Inside them, all characters are interpreted literally, including newlines, tabs, and even backslashes.

// Correct way: use backtickspackage main

import "fmt"

func main() {    message := `Hello,world!`    fmt.Println(message)}// Output:// Hello,// world!

This is ideal for SQL queries, JSON, HTML templates, and any other text where structure matters. However, this leads to the next mistake.

Mistake #3: Extra Spaces and Indentation Inside Raw Strings

When you write code, you indent it for readability. But if you insert a multiline string directly into a function body with indentation, those indents become part of the string.

// Example with "extra" spacespackage main

import "fmt"

func main() {    query := `        SELECT id, name        FROM users        WHERE active = true    `    fmt.Println(query)}// Output (note the leading spaces):////         SELECT id, name//         FROM users//         WHERE active = true//     

The first line of output is empty (because of the newline after the opening backtick), and each subsequent line starts with 8 spaces. This can break logic if the string is used, for example, in os.Exec or during comparison.

How to avoid it? There are two ways. The first is to write the string without indentation, flush to the edge:

query := `SELECT id, nameFROM usersWHERE active = true`

The second is to use concatenation or strings.TrimSpace. But the easiest way is to train yourself not to indent inside raw strings if the whitespace is critical. For SQL queries, this is often not a problem, but for logs or user messages, it can be fatal.

Mistake #4: Forgetting About Escaping in Raw Strings

Raw strings do not support escape sequences. This means that inside backticks is simply two characters: a backslash and the letter 'n', not a newline.

package main

import "fmt"