Using Node JS how do I read a JSON file into server memory

Question

Background I am doing some experimentation with Node js and would like to read a JSON object  either from a text file or a  js file  which is better    into memory so that I can access that object quickly from code   I realize that there are things like Mongo  Alfred  etc out there  but that is not what I need right now  Question How do I read a JSON object out of a text or js file and into server memory using JavaScript Node

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Using fs-extra package is quite simple   Sync   const fs   require  fs-extra    const packageObj   fs readJsonSync    package json   console log packageObj version     Async   const fs   require  fs-extra    const packageObj   await fs readJson    package json   console log packageObj version

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function parseIt        return new Promise function res           try              var fs   require  fs                const dirPath    K   merge-xml-junit  xml-results  master json               fs readFile dirPath  utf8  function err data                   if err  throw err                  res data                       catch err               res err                        async function test        jsonData   await parseIt        var parsedJSON   JSON parse jsonData       var testSuite   parsedJSON  testsuites    testsuite        console log testSuite      test

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https   nodejs org dist latest-v6 x docs api fs html fs fs readfile file options callback    var fs   require  fs       fs readFile   etc passwd    err  data    gt      if  err  throw err    console log data             options fs readFile   etc passwd    utf8   callback     https   nodejs org dist latest-v6 x docs api fs html fs fs readfilesync file options    You can find all usage of Node js at the File System docs  hope this help for you

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If you are looking for a complete solution for Async loading a JSON file from Relative Path with Error Handling       Global variables      Request path module for relative path     const path   require  path        Request File System Module    var fs   require  fs         GET request for the  list user page  router get   listUsers   function  req  res       console log  Got a GET request for list of users             Create a relative path URL     let reqPath   path join   dirname      mock users json           Read JSON from relative path of this file     fs readFile reqPath    utf8   function  err  data              Handle Error        if  err               Handle Success           console log  Success  data               Parse Data to JSON OR           var jsonObj   JSON parse data             Send back as Response           res end  data             else                Handle Error            res end  Error    err                         Directory Structure

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Asynchronous is there for a reason  Throws stone at  mihai  Otherwise  here is the code he used with the asynchronous version      Declare variables var fs   require  fs        obj     Read the file and send to the callback fs readFile  path to file   handleFile      Write the callback function function handleFile err  data        if  err  throw err     obj   JSON parse data         You can now play with your datas

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In Node 8 you can use the built-in util promisify   to asynchronously read a file like this const  promisify    require  util   const fs   require  fs   const readFileAsync   promisify fs readFile   readFileAsync      dirname  my json    encoding   utf8       then contents   gt        const obj   JSON parse contents      console log obj          catch error   gt        throw error

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Sync   var fs   require  fs    var obj   JSON parse fs readFileSync  file    utf8       Async   var fs   require  fs    var obj  fs readFile  file    utf8   function  err  data      if  err  throw err    obj   JSON parse data

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The easiest way I have found to do this is to just use require and the path to your JSON file   For example  suppose you have the following JSON file   test json       firstName    Joe      lastName    Smith      You can then easily load this in your node js application using require  var config   require    test json    console log config firstName         config lastName

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At least in Node v8 9 1  you can just do  var json data   require   path to local file json     and access all the elements of the JSON object

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using node-fs-extra  async await   const readJsonFile   async      gt      try       const myJsonObject   await fs readJson    my json file json        console log myJsonObject       catch  err        console error err         readJsonFile      prints your json object

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So many answers  and no one ever made a benchmark to compare sync vs async vs require  I described the difference in use cases of reading json in memory via require  readFileSync and readFile here

[javascript] Using Node.JS, how do I read a JSON file into (server) memory?

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