How to compare property values ​​of multiple objects?

Question

JavaScript

have a JSON object

var jsonObject = JSON.parse('<?php echo $JSON_database ?>');

it has 3 objects in an array, with the same properties.

Object {id: "6", hierarchy: "0", login: "John", password: "Gregg"}
Object {id: "7", hierarchy: "0", login: "Hunner", password: "james"}

how to pull out all login properties (from 3 objects in the array (and if there are 1000 objects then pull out from 1000)), compare with the loginvalue variable obtained from html?

Answer 1

The matter is that I need to implement vsyazka, mysql -> php -> JSON -> JS -> checking -> login;
To carry out all the processing in the data in JS ....
I wonder if it is possible to pull properties from a set of objects for comparison.
For synchronous work with the database.

Answer 2

var arr = [
  {id: "6", hierarchy: "0", login: "John", password: "Gregg"},
  {id: "7", hierarchy: "0", login: "Hunner", password: "james"}
];

for (var i = 0; i < arr.length; i++) {
  if (arr[i].login == loginValue) {
    alert('Login found!');
    break;
  }
}

Only working with usernames and passwords on the client side is a bad idea

Answer 3

let arr = [
{"id_request" : "29", "st_name" : "В работе", "h_time" : "103"},
{"id_request" : "29", "st_name" : "В работе", "h_time" : "105"},
{"id_request" : "29", "st_name" : "Закрыта", "h_time" : "117"},
{"id_request" : "29", "st_name" : "Открыта", "h_time" : "101"}
];

let max = arr.reduce((acc, curr) => acc.h_time > curr.h_time ? acc : curr);
console.log(max);

let maxIndex = arr.reduce((acc, curr, i) => arr[acc].h_time > curr.h_time ? acc : i, 0);
console.log(maxIndex);

let max_history = request_history.reduce((acc, curr) => Math.floor(new Date(acc.h_time).getTime() / 1000) > Math.floor(new Date(curr.h_time).getTime() / 1000) ? acc : curr);


arr.sort((a, b) => parseFloat(b.h_time) - parseFloat(a.h_time));




let  added_events = ['103', '45', '567'];
let content = arr.filter(function(n) {
        return added_events.indexOf(n.h_time) !== -1;
      });
console.log(content);