Question

如何比较对象的数组和数组，并在新数组

中插入新对象

dayList

我需要将dayArray与const result = [ {'key':'Mon','value':1}, {'key':'Tue','value':5}, {'key':'Wed','value':10}, {'key':'Thu','value':0}, {'key':'Fri','value':18}, {'key':'Sat','value':80}, {'key':'Sun','value':20}, ]进行比较，然后插入新的

#include <iostream>

#include <fstream>

#include <string>
#include <sstream>
#include <vector>

int main()
{
    //establishing constant variables;
    const char Walls = '#';
    const char Mazes = '-';
    const int row = 10;
    const int col = 11;

    //defining strings to pull from text file
    std::string arraysize_sx;
    std::string arraysize_sy;
    std::string start_sx;
    std::string start_sy;
    std::string finish_sx;
    std::string finish_sy;
    std::string walls_s;

    std::ifstream openfile ("input.txt");
    std::ofstream outputfile ("output.txt",std::ios::app);

    //gets points from text file, using , and . as delimiters
    std::getline(openfile, arraysize_sx , ',');
    std::getline(openfile, arraysize_sy, '.');
    std::getline(openfile, start_sx, ',');
    std::getline(openfile, start_sy, '.');
    std::getline(openfile, finish_sx , ',');
    std::getline(openfile, finish_sy , '.');
    std::getline(openfile,walls_s, '.');


    int startx,starty;
    int finishx,finishy;

    //convert string to int
    std::stringstream rowconv(arraysize_sx);
    std::stringstream colconv(arraysize_sy);
    std::stringstream startsx(start_sx);
    std::stringstream startsy(start_sy);
    std::stringstream finishsx(finish_sx);
    std::stringstream finishsy(finish_sy);


//    rowconv >> row;
//    colconv >> col;
    startsx >> startx;
    startsy >> starty;
    finishsx >> finishx;
    finishsy >> finishy;

    //defining the shape of the maze
    char maze [col][row] = {
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
        {'-','-','-','-','-','-','-','-','-','-'},
    };

    maze[startx][starty] = 's';
    maze[finishx+3][finishy] = 'f';
    outputfile << *maze;





    openfile.close();
}

如果可以使用lodash完成吗？

Answer 1

从dayList按键创建Map天。使用Array#map迭代dayArray，如果dayMap中没有这一天，则返回一个空对象：

const dayList = [
    {'key':'Mon','value':1}, 
    {'key':'Tue','value':5},
    {'key':'Wed','value':10},
    {'key':'Fri','value':18},
    {'key':'Sat','value':80},
    {'key':'Sun','value':20},
]

const dayArray = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]

const dayMap = new Map(dayList.map((o) => [o.key, o]))

const result = dayArray.map((key) => dayMap.has(key) ? dayMap.get(key) : { key, value: 0 })

console.log(result);

Answer 2

创建JSON对象数组中所有键的数组。然后找出差异并将差异对象推送到数组。

var dayArray = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
var diff = _.difference(dayArray,_.map(dayList,'key'));
if(diff.length>0){
dayList.push({key:diff[0],value:0});
}
console.log(dayList);

javascript将数组与对象列表进行比较并插入新的数组值

2 个答案: