golang实现高阶函数之filter

 package main

 import "fmt"

 type student struct{
     name string
     grade int8
 }

 func filter(stu []student, f func(s student) bool) []student{
     var r []student

     for _, s := range stu {
         if f(s) == true {
             r = append(r, s)
         }
     }

     return r
 }

 func main() {
     s1 := student{
         "zhangsan",
         ,
     }

     s2 := student{
         "lisi",
         ,
     }

     s3 := student{
         "wanggang",
         ,
     }

     s := []student{s1, s2, s3}

     fmt.Println("all student: ", s)

     var result []student

     result = filter(s, func(s student) bool {
         if s.grade <  {
             return true
         }
         return false
     })

     fmt.Println("less than 90: ", result)
 }

运行结果：

all student:  [{zhangsan } {lisi } {wanggang }]
less than :  [{lisi } {wanggang }]