How To Concatenate Strings in Golang

Concatenation is the process of joining two or more strings together to form a new single string in Go strings. The + operator is the simplest way to concatenate two or more strings in the Go language.

We’ll discuss a number of ways to concatenate strings in golang. The string consists of an immutable chain of arbitrary bytes encoded in UTF-8.

Method 1: Using + Operator

Let’s concatenate string using ‘+’ operator.

package main

import "fmt"

func main() {

        // Creating and initializing strings using var keyword
        var str1 string
        str1 = "Welcome! "

        var str2 string
        str2 = "golanglearn"

        // Concatenating strings using + operator
        fmt.Println("Concatenated string: ", str1+str2)

}

Output:

Concatenated string: Welcome! golanglearn

Method 2: Using bytes.Buffer

We can also create a string by concatenating the bytes of the strings using bytes. Buffer with WriteString() method.it doesn’t generate a new string as like ‘+’ operator.

package main

import (
        "bytes"
        "fmt"
)

func main() {

        // Creating and initializing strings
        var st bytes.Buffer
        
        st.WriteString("g")
        st.WriteString("o")
        st.WriteString("l")
        st.WriteString("a")
        st.WriteString("n")
        st.WriteString("g")
        
        fmt.Println("String 1: ", st.String())

        st.WriteString("l")
        st.WriteString("e")
        st.WriteString("r")
        st.WriteString("n")
        fmt.Println("Concatenated: ", st.String())
}

Output:

String 1: golang
Concatenated: golanglern

Method 3: Using Sprintf

We can also concatenate string using Sprintf() method.

import "fmt"

func main() {

        // Creating and initializing strings
        str1 := "golang"
        str2 := "learn"

        // Concatenating strings using
        // Sprintf() function
        result := fmt.Sprintf("%s%s", str1, str2)
        
        fmt.Println(result)
}

Output:

golanglearn

Method 3: Using Join

The Join() method is part of the string package. This combines all of the items in a string slice into a single string.

Syntax:

func Join(str []string, sep string) string

Where:
str – The string slices.
sep – This is placed between the elements in the final string.

package main

import (
        "fmt"
        "strings"
)

func main() {

        // Creating and initializing slice of string
        myslice := []string{"Hello", "golang",
                        "learn"}

        // Using join() function
        result := strings.Join(myslice, "-")
        fmt.Println(result)
}

Output:

Hello-golang-learn