What is the difference between Go's string literals and string values?

Question

Jayant Kumar · Accepted Answer

Table of Contents
Introduction
In Go, strings are a fundamental data type used to store sequences of characters. However, there are two main ways to represent strings: string literals and string values. Understanding the differences between these two can help in optimizing memory usage and performance when working with string data in Go.
String Literals in Go
A string literal is a constant value in Go that represents a fixed sequence of characters. String literals are written directly in the code, enclosed in double quotes ("...") or backticks (`...`). They are immutable and stored in a read-only section of memory, which means they cannot be modified after they are created.
Characteristics of String Literals

Immutability: String literals are immutable, meaning their content cannot be changed after creation. Any operation that appears to modify a string actually creates a new string.
Memory Efficiency: Since string literals are stored in a read-only section of memory, they can be reused across the program, saving memory.
Syntax:

Double-quoted strings: Used for strings that may contain escape sequences (like 
 or 	).
Backtick strings: Used for raw strings that do not interpret escape sequences.

Example:
package main

import "fmt"

func main() {
    strLiteral := "Hello, World!"      // Double-quoted string literal
    rawStrLiteral := `Hello,
World!`  // Backtick raw string literal
    
    fmt.Println(strLiteral)    // Output: Hello, World!
    fmt.Println(rawStrLiteral) // Output: Hello,
World!
}

String Values in Go
A string value refers to any string data stored in a variable or returned from a function. While a string value might originate from a string literal, it can also come from string manipulation or concatenation operations. String values are also immutable; however, they are managed differently in memory.
Characteristics of String Values

Dynamically Created: String values can result from operations like concatenation, slicing, or function results, making them dynamic and varied in content.
Heap Allocation: Depending on the operation, string values may be allocated on the heap, especially when they are constructed dynamically.
Garbage Collection: String values are managed by Go's garbage collector, which automatically frees memory when the string is no longer referenced.

Example:
package main

import "fmt"

func main() {
    base := "Hello"
    derivedStr := base + ", World!" // String value created through concatenation
    
    fmt.Println(derivedStr) // Output: Hello, World!
}

Practical Examples
Example : String Concatenation
Concatenating multiple string literals:
package main

import "fmt"

func main() {
    str1 := "Hello"
    str2 := "World"
    combined := str1 + " " + str2 // Creates a new string value
    
    fmt.Println(combined) // Output: Hello World
}

Example : String Manipulation
Manipulating string values:
package main

import "fmt"

func main() {
    original := "Hello, Go!"
    modified := original[7:] // Slicing a string value
    
    fmt.Println(modified) // Output: Go!
}

Conclusion
In Go, string literals and string values both represent sequences of characters but differ in their immutability, memory management, and usage. String literals are constant, immutable values defined directly in the code, while string values can be dynamically created and manipulated. Understanding these differences helps in writing more efficient Go code, particularly in memory management and performance-sensitive applications.

What is the difference between Go's string literals and string values?

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