How to compare a value against an array

Question

This is my JSON object and I need to check for a particular id and get the date

 [
        {
          "id": "9b3b835b",
          "date": "Tue Mar 27 10:23:18 UTC 2018"
        },
        {
          "id": "57eab193",
          "date": "Thu Mar 29 14:45:23 UTC 2018"
        },
        {
          "id": "440f0cd9",
          "date": "Thu Mar 29 15:12:00 UTC 2018"
        },
 ]

You have an *array* there, not an object. `arr.find(obj => obj.id === id).date;` (well, technically an array is an object, but if you're dealing with an array, you should call it an array instead) — CertainPerformance, Apr 12 '18 at 02:46
@CertainPerformance This will cause TypeErrors if the find method doesnt find anything (just a word of caution to the uneducated reader) — Abid Hasan, Apr 12 '18 at 02:49
You should at least post what have you tried, or even searching, before making a question — iagowp, Apr 12 '18 at 03:00

score 1 · Accepted Answer · edited Apr 17 '18 at 12:44

yourVariable = [{
    "id": "9b3b835b",
    "date": "Tue Mar 27 10:23:18 UTC 2018"
  },
  {
    "id": "57eab193",
    "date": "Thu Mar 29 14:45:23 UTC 2018"
  },
  {
    "id": "440f0cd9",
    "date": "Thu Mar 29 15:12:00 UTC 2018"
  },
];

for (keys in yourVariable) {
  // supposing id your are looking for is 57eab193
  if (yourVariable[keys].id == '57eab193') {
    console.log(yourVariable[keys].date)
  }
}

score 0 · Answer 2 · answered Apr 12 '18 at 02:57

You can use the function find to get a specific according to a condition.

This alternative uses the logical operator || just to avoid access error over an undefined value.

var array = [{
    "id": "9b3b835b",
    "date": "Tue Mar 27 10:23:18 UTC 2018"
  },
  {
    "id": "57eab193",
    "date": "Thu Mar 29 14:45:23 UTC 2018"
  },
  {
    "id": "440f0cd9",
    "date": "Thu Mar 29 15:12:00 UTC 2018"
  },
];

var date = (array.find(o => o.id === "440f0cd9") || {}).date;
console.log(date);

date = (array.find(o => o.id === "ele") || {}).date;
console.log(date);

How to compare a value against an array

2 Answers2