Go Struct Validator with Playground

package main

import (
    "fmt"
    "github.com/go-playground/validator/v10"
)

type CreateUser struct {
    Name  string `json:"name"  validate:"required,min=2,max=100"`
    Email string `json:"email" validate:"required,email"`
    Age   int    `json:"age"   validate:"gte=18"`
}

var validate = validator.New()

func main() {
    u := CreateUser{Name: "J", Email: "bad", Age: 15}
    if err := validate.Struct(u); err != nil {
        fmt.Println(err)
    }
}