Let's talk about how to use nodejs to add, delete, modify and check local json files

var fs = require('fs');var params = {
    "id":5,
    "name":"白眉鹰王"}//在真实的开发中id肯定是随机生成的而且不会重复的，下一篇写如何生成随机切不会重复的随机数，现在就模拟一下假数据//写入json文件选项function writeJson(params){
    //现将json文件读出来
    fs.readFile('./mock/person.json',function(err,data){
        if(err){
            return console.error(err);
        }
        var person = data.toString();//将二进制的数据转换为字符串
        person = JSON.parse(person);//将字符串转换为json对象
        person.data.push(params);//将传来的对象push进数组对象中
        person.total = person.data.length;//定义一下总条数，为以后的分页打基础
        console.log(person.data);
        var str = JSON.stringify(person);//因为nodejs的写入文件只认识字符串或者二进制数，所以把json对象转换成字符串重新写入json文件中
        fs.writeFile('./mock/person.json',str,function(err){
            if(err){
                console.error(err);
            }
            console.log('----------新增成功-------------');
        })
    })}writeJson(params)//执行一下;

var fs = require('fs');//删除json文件中的选项function deleteJson(id){
    fs.readFile('./mock/person.json',function(err,data){
        if(err){
            return console.error(err);
        }
        var person = data.toString();
        person = JSON.parse(person);
        //把数据读出来删除
        for(var i = 0; i <p><img src="https://img.php.cn/upload/article/000/000/024/958beac2084a4988806a16de07120258-4.png" alt="Lets talk about how to use nodejs to add, delete, modify and check local json files"></p><p><img src="https://img.php.cn/upload/article/000/000/024/57338fe94b8097b8ba5e3adc61d9c0c0-5.png" alt="Lets talk about how to use nodejs to add, delete, modify and check local json files"></p> <p>The fifth one was deleted</p><p><strong>##3. Change</strong></p><p>The json file at the beginning looks like this<br><img src="https://img.php.cn/upload/article/000/000/024/57338fe94b8097b8ba5e3adc61d9c0c0-6.png" alt="Lets talk about how to use nodejs to add, delete, modify and check local json files"></p> <p>The code below</p><pre class="brush:php;toolbar:false">var fs = require('fs');var params = {
    "name":"孙悟空"}function changeJson(id,params){
    fs.readFile('./mock/person.json',function(err,data){
        if(err){
            console.error(err);
        }
        var person = data.toString();
        person = JSON.parse(person);
        //把数据读出来,然后进行修改
        for(var i = 0; i <p>The result is as follows</p><p><img src="https://img.php.cn/upload/article/000/000/024/57338fe94b8097b8ba5e3adc61d9c0c0-7.png" alt="Lets talk about how to use nodejs to add, delete, modify and check local json files"></p><p>Look at the json file</p><p><img src="https://img.php.cn/upload/article/000/000/024/e8c5e5bba1bc620b84cd435324187741-8.png" alt="Lets talk about how to use nodejs to add, delete, modify and check local json files"></p><p>Modify success! ! ! ! </p><p><strong>##4. Check</strong></p><p>Now simulate paging</p><p>First look at what the json file looks like</p><p><img src="https://img.php.cn/upload/article/000/000/024/e8c5e5bba1bc620b84cd435324187741-9.png" alt="Lets talk about how to use nodejs to add, delete, modify and check local json files"> </p><p>The above code</p><pre class="brush:php;toolbar:false">var fs = require('fs');//通过传回来的页数，进行分页模拟function pagination(p,s){
    //p为页数，比如第一页传0，第二页传1,s为每页多少条数据
    fs.readFile('./mock/person.json',function(err,data){
        if(err){
            console.error(err);
        }
        var person = data.toString();
        person = JSON.parse(person);
        //把数据读出来
        //console.log(person.data);
        var length = person.data.length;
        var pagePerson = person.data.slice(s*p,(p+1)*s);
        console.log('------------------------查询成功pagePerson');
        console.log(pagePerson);
    })}pagination(0,6);//查询第一页，每页的数据条数为6条