JavaScript Array find Method

The find method works just like the filter method, but instead of returning an array, it returns the first element for which the iteration function returns a true value.  Here’s an example:

var users = [
  { id: 1, admin: false },
  { id: 2, admin: false },
  { id: 3, admin: true }
];

var admin = users.find(function(user){
    return user.admin;
});

console.log(admin);

Here’s another example using the arrow function notation:

var accounts = [
  { balance: -10 },
  { balance: 12 },
  { balance: 0 }
];

var account = accounts.find((account)=>{return account.balance === 12});

console.log(account);

Here’s an example that includes a function with a criteria object. In this case Object.keys(criteria)[0] returns the name of the first property of the criteria object.

function findWhere(array, criteria) {
  var property = Object.keys(criteria)[0];
  return array.find(function(item){
      return item[property] === criteria[property];
  });
}

var ladders = [
  { id: 1, height: 20 },
  { id: 3, height: 25 }
];
var ladder = findWhere(ladders, { height: 25 })

console.log(ladder);