lancet/docs/structs/field_zh-CN.md

Field

Field 包封装了一个抽象的Field结构体，提供了操作struct属性的相关函数

源码:

• https://github.com/duke-git/lancet/blob/main/structs/field.go

用法:

import (
    "github.com/duke-git/lancet/v2/structs"
)

目录:

• Tag
• Name
• Value
• Kind
• IsEmbedded
• IsExported
• IsZero
• IsSlice

注意：由于Field继承于Struct，所以同样拥有Struct所有方法，如下：

• ToMap
• Fields
• Field
• IsStruct

API 文档:

Tag

获取`Field`的`Tag`，默认的tag key是json

函数签名:

func (f *Field) Tag() *Tag

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string `json:"name,omitempty"`
    }
    p1 := &Parent{"111"}

    s := structs.New(p1)
    n, _ := s.Field("Name")
    tag := n.Tag()

    fmt.Println(tag.Name)
    
    // Output:
    // name
}

Value

获取`Field`属性的值

函数签名:

func (f *Field) Value() any

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string `json:"name,omitempty"`
    }
    p1 := &Parent{"111"}

    s := structs.New(p1)
    n, _ := s.Field("Name")
    
    fmt.Println(n.Value())
    
    // Output: 
    // 111
}

IsEmbedded

判断属性是否为嵌入

函数签名:

func (f *Field) IsEmbedded() bool

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string
    }
    type Child struct {
        Parent
        Age int
    }
    c1 := &Child{}
    c1.Name = "111"
    c1.Age = 11

    s := structs.New(c1)
    n, _ := s.Field("Name")
    a, _ := s.Field("Age")
    
    fmt.Println(n.IsEmbedded())
    fmt.Println(a.IsEmbedded())
    
    // Output: 
    // true
    // false
}

IsExported

判断属性是否导出

函数签名:

func (f *Field) IsExported() bool

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string
        age  int
    }
    p1 := &Parent{Name: "11", age: 11}
    s := structs.New(p1)
    n, _ := s.Field("Name")
    a, _ := s.Field("age")
    
    fmt.Println(n.IsExported())
    fmt.Println(a.IsExported())
    
    // Output: 
    // true
    // false
}

IsZero

判断属性是否为零值

函数签名:

func (f *Field) IsZero() bool

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string
        Age  int
    }
    p1 := &Parent{Age: 11}
    s := structs.New(p1)
    n, _ := s.Field("Name")
    a, _ := s.Field("Age")
    
    fmt.Println(n.IsZero())
    fmt.Println(a.IsZero())
    
    // Output: 
    // true
    // false
}

Name

获取属性名

函数签名:

func (f *Field) Name() string

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string
        Age  int
    }
    p1 := &Parent{Age: 11}
    s := structs.New(p1)
    n, _ := s.Field("Name")
    a, _ := s.Field("Age")
    
    fmt.Println(n.Name())
    fmt.Println(a.Name())
    
    // Output: 
    // Name
    // Age
}

Kind

获取属性Kind

函数签名:

func (f *Field) Kind() reflect.Kind

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string
        Age  int
    }
    p1 := &Parent{Age: 11}
    s := structs.New(p1)
    n, _ := s.Field("Name")
    a, _ := s.Field("Age")
    
    fmt.Println(n.Kind())
    fmt.Println(a.Kind())
    
    // Output: 
    // string
    // int
}

IsSlice

判断属性是否是切片

函数签名:

func (f *Field) IsSlice() bool

示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/structs"
)

func main() {
    type Parent struct {
        Name string
        arr  []int
    }

    p1 := &Parent{arr: []int{1, 2, 3}}
    s := structs.New(p1)
    a, _ := s.Field("arr")
    
    fmt.Println(a.IsSlice())
    
    // Output: 
    // true
}