How to fmt.Printf an integer with thousands comma

Question

Does Go\'s fmt.Printf support outputting a number with the thousands comma?

fmt.Printf(\"%d\", 1000) outputs 1000, what format

Answer 1

The package humanize can do the magic! Refer the documentation of this package here. To use this package, install it first by using a tool like Git SCM. If you are using Git Bash, open the shell window and type:

go get -u github.com/dustin/go-humanize

Once this is done, you can use the following solution code (Say, main.go):

package main

import (
    "fmt"
    "github.com/dustin/go-humanize"
)

func main() {
    fmt.Println(humanize.Commaf(float64(123456789)));
    fmt.Println(humanize.Commaf(float64(-1000000000)));
    fmt.Println(humanize.Commaf(float64(-100000.005)));
    fmt.Println(humanize.Commaf(float64(100000.000)));
}

There are other variations to Commaf like BigComma, Comma, BigCommaf etc. which depends on the data type of your input.

So, on running this program using the command:

go run main.go

You will see an output such as this:

123,456,789
-1,000,000,000
-100,000.005
100,000