当给定的数据校验规则中不包含required*规则时，表示该规则不是一个必须规则，当属性值为nil或者空字符串时，将会忽略其校验。

示例1，空字符串

package main
import (
    "fmt"
    "github.com/gogf/gf/v2/frame/g"
    "github.com/gogf/gf/v2/os/gctx"
)
func main() {
    type Params struct {
        Page      int    `v:"required|min:1         # page is required"`
        Size      int    `v:"required|between:1,100 # size is required"`
        ProjectId string `v:"between:1,10000        # project id must between {min}, {max}"`
    }
    var (
        ctx = gctx.New()
        obj = &Params{
            Page: 1,
            Size: 10,
        }
    )  
    err := g.Validator().Data(obj).Run(ctx)  
    fmt.Println(err)
    // Output:
    // <nil>
}

示例2，空指针属性

package main
import (
    "fmt"
    "github.com/gogf/gf/v2/container/gvar"
    "github.com/gogf/gf/v2/frame/g"
    "github.com/gogf/gf/v2/os/gctx"
)
func main() {
    type Params struct {
        Page      int       `v:"required|min:1         # page is required"`
        Size      int       `v:"required|between:1,100 # size is required"`
        ProjectId *gvar.Var `v:"between:1,10000        # project id must between {min}, {max}"`
    }
    var (
        ctx = gctx.New()
        obj = &Params{
            Page: 1,
            Size: 10,
        }
    )  
    err := g.Validator().Data(obj).Run(ctx)  
    fmt.Println(err)
    // Output:
    // <nil>
}

示例3，空整型属性

需要注意的是，如果键值为0或者false，参数值将仍然会被校验。

package main
import (
    "fmt"
    "github.com/gogf/gf/v2/frame/g"
    "github.com/gogf/gf/v2/os/gctx"
)
func main() {
    type Params struct {
        Page      int `v:"required|min:1         # page is required"`
        Size      int `v:"required|between:1,100 # size is required"`
        ProjectId int `v:"between:1,10000        # project id must between {min}, {max}"`
    }
    var (
        ctx = gctx.New()
        obj = &Params{
            Page: 1,
            Size: 10,
        }
    )
    err := g.Validator().Data(obj).Run(ctx)  
    fmt.Println(err)
    // Output:
    // <nil>
}

执行后，终端输出：

project id must between 1, 10000