Find object by property in JSON array

Question

I have problem with get string in JSON data. Format as below:

[
  { "name": "Alice", "age": "20" },
  { "id": "David", "last": "25" },
  { "id": "John", "last": "30" }
]

Sometime it changes position together, John from 3rd place go to 2nd place:

[
  { "name": "Alice", "age": "20" },
  { "name": "John", "age": "30" },
  { "name": "David", "age": "25"}
]

If i use data[3].age to get John's age, and data change position, I will get David's age.

Is there any method I can use to find the object with name David and get the age value?

Answer 1

You can use array.find() method as,

var myArray = [
  {
    "name": "Alice",
    "age": "20"
  },
  {
    "name": "John",
    "age": "30"
  },
  {
    "name": "David",
    "age": "25"
  }
];

//Here you are passing the parameter name and getting the age 
//Find will get you the first matching object
var result = myArray.find(t=>t.name ==='John').age;
console.log(result);

Answer 2

It's better to use array.filter() (better browser support)

myArray.filter(function(el){return el.name == "John"})[0].age