golang將切片或數組進行分組

例子一：
golang 數組分割
需求：給定一個數組和一個正整數，要求把數組分割成多個正整數大小的數組，如果不夠分，則最后一個數組分到剩余的所有元素。

示例1：

數組：[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]，正整數：2
期望結果: [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]

示例2：

數組：[1, 2, 3, 4, 5, 6, 7, 8, 9]，正整數：2
期望結果: [[1, 2], [3, 4], [5, 6], [7, 8], [9]]

代碼

package main
 
import (
    "fmt"
)

func main(){

	arr := []int{1, 2, 3, 4, 5, 6, 7, 8, 9,10}	//[[1 2] [3 4] [5 6] [7 8] [9 10]]
        fmt.Println(arr) //[1 2 3 4 5 6 7 8 9 10]
	//arr := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}	//[[1 2] [3 4] [5 6] [7 8] [9]]

	res:= arrayInGroupsOf(arr,2)
	fmt.Println(res)
}

func arrayInGroupsOf(arr []int, num int64) [][]int {
	max := int64(len(arr))
	//判斷數組大小是否小於等於指定分割大小的值，是則把原數組放入二維數組返回
	if max <= num {
		return [][]int{arr}
	}
	//獲取應該數組分割為多少份
	var quantity int64
	if max%num == 0 {
		quantity = max / num
	} else {
		quantity = (max / num) + 1
	}
	//聲明分割好的二維數組
	var segments = make([][]int, 0)
	//聲明分割數組的截止下標
	var start, end, i int64
	for i = 1; i <= quantity; i++ {
		end = i*num
		if i != quantity {
			segments = append(segments, arr[start:end])
		} else {
			segments = append(segments, arr[start:])
		}
		start = i*num
	}
	return segments
}

原文鏈接：https://blog.csdn.net/MCJPAO/article/details/108431657

例子二

golang將切片或數組根據某個字段進行分組

package main

import (
	"fmt"
	"sort"
)

type Person struct {
	Name string
	Age int
}

func main() {
	p1 := Person{"Tom",20}
	p2 := Person{"Lily",21}
	p3 := Person{"Linda",23}
	p4 := Person{"Jass",25}
	p5 := Person{"Tonny",20}
	p6 := Person{"Pite",25}
	p7 := Person{"Paul",21}
	p8 := Person{"Kriss",27}
	p9 := Person{"Jake",23}
	p10 := Person{"Rose",20}

	personList := []Person{}
	personList = append(personList,p1,p2,p3,p4,p5,p6,p7,p8,p9,p10)
	fmt.Println("分組前的數據:",personList)
	fmt.Println("分組后的數據:",splitSlice(personList))
}

//按某個字段排序
type sortByAge []Person

func (s sortByAge) Len() int           { return len(s) }
func (s sortByAge) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
func (s sortByAge) Less(i, j int) bool { return s[i].Age < s[j].Age}



//切片分組
func splitSlice(list []Person)  [][]Person {
	sort.Sort(sortByAge(list))
	returnData := make([][]Person,0)
	i:= 0
	var j int
	for {
		if i >= len(list) {
			break
		}
		for j = i + 1; j< len(list) && list[i].Age == list [j].Age; j++ {}

		returnData = append(returnData,list[i:j])
		i = j
	}
	return returnData
}

輸出：

分組前的數據: [{Tom 20} {Lily 21} {Linda 23} {Jass 25} {Tonny 20} {Pite 25} {Paul 21} {Kriss 27} {Jake 23} {Rose 20}]
分組后的數據: [[{Tom 20} {Rose 20} {Tonny 20}] [{Lily 21} {Paul 21}] [{Linda 23} {Jake 23}] [{Pite 25} {Jass 25}] [{Kriss 27}]]