cnpj

README

Go CNPJ

A Go module to validate CNPJ numbers (Brazilian companies unique identifier for the Federal Revenue).

package main

import "github.com/cuducos/go-cnpj"


func main() {
	// these return true
	cnpj.IsValid("11222333000181")
	cnpj.IsValid("11.222.333/0001-81")

	// these return false
	cnpj.IsValid("11.111.111/1111-11")
	cnpj.IsValid("12.345.678 9012-34")
	cnpj.IsValid("AB.CDE.FGH/IJKL-MN")
	cnpj.IsValid("123")

	// this returns 11111111111111
	cnpj.Unmask("11.111.111/1111-11")

	// this returns 11.111.111/1111-11
	cnpj.Mask("11111111111111")
}

Based on Go CPF ❤️

Documentation

Index

• func Base(n string) string
• func CheckDigit(n string) string
• func IsValid(n string) bool
• func Mask(n string) string
• func Order(n string) string
• func Unmask(n string) string

Examples

• Base (Invalid)
• Base (ValidMasked)
• Base (ValidUnmasked)
• CheckDigit (Invalid)
• CheckDigit (ValidMasked)
• CheckDigit (ValidUnmasked)
• IsValid (Invalid)
• IsValid (ValidMasked)
• IsValid (ValidUnmasked)
• Mask (Invalid)
• Mask (Valid)
• Order (Invalid)
• Order (ValidMasked)
• Order (ValidUnmasked)
• Unmask

Functions

func Base

func Base(n string) string

Base returns the first 8 digits of the CNPJ number

Example (Invalid)

fmt.Println(Base("123"))

Example (ValidMasked)

fmt.Println(Base("11.222.333/0001-81"))

Output:

11222333

Example (ValidUnmasked)

fmt.Println(Base("11222333000181"))

Output:

11222333

func CheckDigit

func CheckDigit(n string) string

CheckDigit returns the last 2 digits of the CNPJ number.

Example (Invalid)

fmt.Println(CheckDigit("123"))

Example (ValidMasked)

fmt.Println(CheckDigit("11.222.333/0001-81"))

Output:

81

Example (ValidUnmasked)

fmt.Println(CheckDigit("11222333000181"))

Output:

81

func IsValid

func IsValid(n string) bool

IsValid checks whether CNPJ number is valid or not

Example (Invalid)

fmt.Println(IsValid("11.111.111/1111-11"))

Output:

false

Example (ValidMasked)

fmt.Println(IsValid("11.222.333/0001-81"))

Output:

true

Example (ValidUnmasked)

fmt.Println(IsValid("11222333000181"))

Output:

true

func Mask

func Mask(n string) string

Mask returns the CNPJ number formatted

Example (Invalid)

fmt.Println(Mask("42"))

Output:

42

Example (Valid)

fmt.Println(Mask("11111111111111"))

Output:

11.111.111/1111-11

func Order

func Order(n string) string

Order returns the 9th, 10th, 11th and 12th digits of the CNPJ number.

Example (Invalid)

fmt.Println(Order("123"))

Example (ValidMasked)

fmt.Println(Order("11.222.333/0001-81"))

Output:

0001

Example (ValidUnmasked)

fmt.Println(Order("11222333000181"))

Output:

0001

func Unmask

func Unmask(n string) string

Unmask removes any non-digit (numeric) from the CNPJ number

Example

fmt.Println(Unmask("11.111.111/1111-11"))

Output:

11111111111111