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Go int to string

last modified September 16, 2020

Go int to string conversion tutorial shows how to convert integers to strings in Golang.

Go int to string conversion

Integer to string conversion is a type conversion or type casting, where an entity of integer data type is changed into string one.

In Go, we can perform the int to string conversion with the strconv.FormatInt, strconv.Itoa, or fmt.Sprintf functions.

The strconv package implements conversions to and from string representations of basic data types.

Go int to string with Itoa

The Itoa is a convenience function which convers an integer to a string. 

func Itoa(i int) string

The Itoa is equivalent to FormatInt(int64(i), 10).

int2str.go
package main

import (
    "fmt"
    "strconv"
)

func main() {

    var apples int = 6

    n := strconv.Itoa(apples)
    msg := "There are " + n + " apples"
    fmt.Println(msg)

    fmt.Printf("%T\n", apples)
    fmt.Printf("%T\n", n)
}

In the example, we convert the number of apples into a string to build a message. Later, we output the type of the apples and n variables. 

$ go run int2str.go 
There are 6 apples
int
string

This is the output.

Go int to string with strconv.FormatInt

The strconv.FormatInt returns the string representation of a value in the given base; where for 2 <= base <= 36.

int2str2.go
package main

import (
    "fmt"
    "strconv"
)

func main() {

    var file_size int64 = 1544466212

    file_size_s := strconv.FormatInt(file_size, 10)

    msg := "The file size is " + file_size_s + " bytes"
    fmt.Println(msg)
}

In the example, we convert the file_size variable, which has type int64, to a string with strconv.FormatInt. 

$ go run int2str2.go 
The file size is 1544466212 bytes

This is the output.

Go int to string with fmt.Sprintf

Another way to convert an integer to a string is to use the fmt.Sprintf function. The function formats according to a format specifier and returns the resulting string.

int2str3.go
package main

import (
    "fmt"
)

func main() {

    var apples int = 6

    msg := fmt.Sprintf("There are %d apples", apples)
    fmt.Println(msg)
}

The fmt.Sprintf formats a new string; it replaces the %d specifier with an integer value.

In this tutorial, we have shown how to perform int to string conversions in Go.

List all Go tutorials.