CODEWITHSUNDEEP
arraysnode.jssearchfindcontains
khaos11
khaos11

Reputation: 63

Search node js array for partial match with variable, return index or value

Hello all I'm new to node and js - trying to make a small bot for a small discord channel , I've kinda hit a wall and can't find a solution.

I am trying to store user input data and recall it later. So far I have this to store the data as a json file.

data[user_id] = value_set
var out_data = JSON.stringify(data);
fs.writeFile('users.json', out_data);

And would look like this:

{"35978432146597841":"String.1","32146879124653147":"String.2"}

Now I want to recall the String.X value later based on the user's id. And this is where I am stuck. I figured I'd need to read the json file and transfer it to an array.

I think I successfully made it an array with the following:

var in_data = fs.readFileSync('users.json');
var data = JSON.parse(in_data);

var arr = []
for(var i in data){
arr.push([i, data [i]]);}

As... console.log(arr[1]);

shows: ['32146879124653147','String.2']

But I cannot figure out how to search that array by the user's id (user_id) to either locate the index and then split the value or even better just pull the value.

Everything I have tried to find the 'String.X' by the user_id has has failed. So what do I need to do to pull 'String.2' if I only know '32146879124653147'.

Any help will be appreciated. Thanks.

SOLUTION

var fs = require("fs");
var in_data = fs.readFileSync('users.json');
var data = JSON.parse(in_data);
var arr = [];

for(var i in data){
    arr.push({
            User:i,
            Input:data [i]
            });
        }
var value = arr.find(x => x.User === id);
var f_value = value.Input;
console.log(f_value);

OR

const userfile = require("./users.json");
var f_value = userfile[userID];

Upvotes: 1

Views: 1456

Answers (3)

khaos11
khaos11

Reputation: 63

After much help from Jay this is the answer I came up with.

var fs = require("fs");
var in_data = fs.readFileSync('users.json');
var data = JSON.parse(in_data);
var arr = [];

for(var i in data){
    arr.push({
            User:i,
            Input:data [i]
            });
        }
var value = arr.find(x => x.User === userID);
var f_value = value.Input;
console.log(f_value);

OTHER

I have since found an easier way to accomplish the above, without fs, or creating an array. 

const userfile = require("./users.json");
var f_value = userfile[userID];

Upvotes: 1

Jay Hamilton
Jay Hamilton

Reputation: 114

You can use find(). In your example, it will return the first key/value that matches, or undefined if there is no match.

var in_data = fs.readFileSync('users.json');
var data = JSON.parse(in_data);

let obj = {}
for(var i in data){

obj[i]:data [i];

let value = obj.find(value => id)
//if id = '32146879124653147' 
// then the 32146879124653147: 'String.2' key/value would be returned

Upvotes: 0

Ashim Paul
Ashim Paul

Reputation: 100

You need to push the items separately and then loop over it skipping by 2 elements in the array.

var fs = require("fs");

var in_data = fs.readFileSync('users.json');
var data = JSON.parse(in_data);

var arr = []
for(var i in data){
  arr.push(i);
  arr.push(data[i]);
}

console.log("Printing arr...");
  for(var i=0; i<arr.length; i++) {
    console.log("arr[" + i + "]= " + arr[i]);
  }

  // Check if 32146879124653147 is found

  console.log("Checking 32146879124653147...");
  for (var i=0; i<arr.length; i+=2) {

    if (arr[i] === "32146879124653147") {
      console.log("Found " + arr[i+1]);
    }
  }

Upvotes: 0

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