golang中使用 sort.Interface 实现复杂多级排序

举两个例子说明 sort.Interface实现多级排序。例子 1学生成绩排序先按成绩降序成绩相同按姓名升序package main import ( fmt sort ) type Student struct { Name string Score int } type ByScoreAndName []Student func (s ByScoreAndName) Len() int { return len(s) } func (s ByScoreAndName) Swap(i, j int) { s[i], s[j] s[j], s[i] } func (s ByScoreAndName) Less(i, j int) bool { // 第一级按分数降序分数高的排前面 if s[i].Score ! s[j].Score { return s[i].Score s[j].Score } // 第二级分数相同时按姓名升序 return s[i].Name s[j].Name } func main() { students : []Student{ {Alice, 85}, {Bob, 90}, {Charlie, 85}, {David, 90}, } sort.Sort(ByScoreAndName(students)) for _, s : range students { fmt.Printf(%s: %d\n, s.Name, s.Score) } // 输出: // Bob: 90 // David: 90 // Alice: 85 // Charlie: 85 }例子 2员工排序先按部门升序部门相同按工资降序工资相同按工号升序package main import ( fmt sort ) type Employee struct { ID int Department string Salary float64 } type ByDeptSalaryID []Employee func (e ByDeptSalaryID) Len() int { return len(e) } func (e ByDeptSalaryID) Swap(i, j int) { e[i], e[j] e[j], e[i] } func (e ByDeptSalaryID) Less(i, j int) bool { // 第一级按部门升序 if e[i].Department ! e[j].Department { return e[i].Department e[j].Department } // 第二级部门相同时按工资降序 if e[i].Salary ! e[j].Salary { return e[i].Salary e[j].Salary } // 第三级工资相同时按工号升序 return e[i].ID e[j].ID } func main() { employees : []Employee{ {103, Engineering, 75000}, {101, Engineering, 80000}, {102, Engineering, 80000}, {201, Sales, 70000}, {202, Sales, 75000}, } sort.Sort(ByDeptSalaryID(employees)) for _, emp : range employees { fmt.Printf(ID: %d, Dept: %s, Salary: %.2f\n, emp.ID, emp.Department, emp.Salary) } // 输出: // ID: 101, Dept: Engineering, Salary: 80000.00 // ID: 102, Dept: Engineering, Salary: 80000.00 // ID: 103, Dept: Engineering, Salary: 75000.00 // ID: 202, Dept: Sales, Salary: 75000.00 // ID: 201, Dept: Sales, Salary: 70000.00 }