golang 切片和map查询比较

Posted 2022-12-24 nyist-xsk

package main

import (
    "fmt"
    "time"
)

var testTimeSlice = []string"aa", "bb", "cc", "dd", "ee", "aa", "zz"

var testTimeMap = map[string]bool"aa": true, "bb": true, "cc": true, "dd": true, "ee": true, "ff": true, "zz": true

//以上为第一组查询测试数据

var testTimeSlice2 = [] string"aa", "bb", "cc", "dd", "ee", "aa", "aa", "bb", "cc", "dd", "ee", "aa", "aa", "bb", "cc", "dd", "ee", "aa", "aa", "bb", "cc", "dd", "ee", "aa", "i", "j", "l", "m", "n", "o", "p", "q", "k", "x", "y", "z",
    "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "zz"

var testTimeMap2 = map[string]bool"aa": true, "bb": true, "cc": true, "dd": true, "ee": true, "ff": true, "qq": true, "ww": true, "rr": true, "tt": true, "zz": true, "uu": true, "ii": true, "oo": true, "pp": true, "lk": true, "kl": true, "jk": true, "kj": true, "hl": true, "lh": true, "fg": true, "gfdd": true, "df": true, "fd": true,
    "i": true, "j": true, "l": true, "m": true, "n": true, "o": true, "p": true, "q": true, "k": true, "x": true, "y": true, "z": true,
    "1": true, "2": true, "3": true, "4": true, "5": true, "6": true, "7": true, "8": true, "9": true, "10": true

//以上为第二组查询测试数据

func testSlice(a []string) 
    now := time.Now()

    for j := 0; j < 100000; j++ 
        for _, v := range a 
            if v == "zz" 
                break
            
        
    
    finish1 := time.Since(now)
    fmt.Println(finish1)


func testMap(a map[string]bool) 
    now := time.Now()
    for j := 0; j < 100000; j++ 
        if ok := a["zz"]; ok
            continue
        
    
    finish2 := time.Since(now)
    fmt.Println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!")
    fmt.Println(finish2)
    fmt.Println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!")


func main()
    //slice查询是遍历方式，时间复杂度是O(n), map查询是hash映射
    //当数据量小的时候切片查询比map快，但是数据量大的时候map的优势就体现出来了
    testSlice(testTimeSlice) //999.8μs
    testMap(testTimeMap) //4.9961ms
    testSlice(testTimeSlice2) //5.0147ms
    testMap(testTimeMap2) //3.0003ms