How to Convert an int32 & int64 to string in Go

To Convert an int to string in Go, use strconv.Itoa()(int32 to string) and strconv.FormatInt()(int64 to string) functions which are part of Go’s strconv package.

We will go through an example to understand them further.

Create a file named ‘convert-int-to-string.go’ and will write code to convert both int32 and int64 to string.

int32 to string #

To convert int32 to string use strconv.Itoa() function.

strconv.Itoa accepts parameter of type int32 and converts it to string.

package main

import (
    "strconv"
    "fmt"
)

func main() {
    var intValue int = 100
    var stringValue string
    stringValue = strconv.Itoa(intValue)
    fmt.Printf("%T, %v\n",intValue,intValue)
    fmt.Printf("%T, %v\n",stringValue,stringValue)
}

Run the ‘convert-int-to-string.go’ file.

> go run convert-int-to-string.go
int, 100
string, 100

int64 to string #

As strconv.Itoa function accepts only int32 variables, if you try to use variable of type int64 you will get following error.

cannot use intValue (type int64) as type int in argument to strconv.Itoa

To convert int64 to string we can use strconv.FormatInt()

package main

import (
    "strconv" 
    "fmt"
)
func main() {
    var int64Value int64 = 100
    var stringValue string
    stringValue = strconv.FormatInt(int64Value, 10)
    fmt.Printf("%T, %v\n",int64Value,int64Value)
    fmt.Printf("%T, %v\n",stringValue,stringValue)
}

In the above example, I am passing second parameter as 10 to the strconv.FormatInt().

The second parameter represents the base i.e., decimal or hexadecimal etc.

10 represents decimal numbers.

Now run the the program

> go run .\convert-int-to-string.go
int64, 100
string, 100

To get the hexa decimal string pass second parameter as 16 as shown below

var n int64 = 100
hexaDecimal := strconv.FormatInt(n, 16)
fmt.Printf("%T, %v\n",hexaDecimal,hexaDecimal)

output:
string, 64

Even we can use strconv.FormatInt to convert int32 to string.

var nInt32 int = 100
nstring := strconv.FormatInt(int64(nInt32), 10)
fmt.Printf("%T, %v\n",nstring,nstring)

output:
string, 100