JavaScript Array find()

let numbers = [1, 3, 4, 9, 8];

// function to check even number
function isEven(element) {
  return element % 2 == 0;
}

// get the first even number
let evenNumber = numbers.find(isEven);
console.log(evenNumber);

// Output: 4

find() Syntax

The syntax of the find() method is:

arr.find(callback(element, index, arr),thisArg)

Here, arr is an array.

find() Parameters

The find() method takes in:

• callback - Function to execute on each element of the array. It takes in:
  • element - The current element of array.
• thisArg (optional) - Object to use as this inside callback.

find() Return Value

• Returns the value of the first element in the array that satisfies the given function.
• Returns undefined if none of the elements satisfy the function.

Example 1: Using find() method

function isEven(element) {
  return element % 2 == 0;
}

let randomArray = [1, 45, 8, 98, 7];

let firstEven = randomArray.find(isEven);
console.log(firstEven); // 8

// using arrow operator
let firstOdd = randomArray.find((element) => element % 2 == 1);
console.log(firstOdd); // 1

Output

8
1

Example 2: find() with Object elements

const team = [
  { name: "Bill", age: 10 },
  { name: "Linus", age: 15 },
  { name: "Alan", age: 20 },
  { name: "Steve", age: 34 },
];

function isAdult(member) {
  return member.age >= 18;
}

console.log(team.find(isAdult)); // { name: 'Alan', age: 20 }

// using arrow function and deconstructing
let adultMember = team.find(({ age }) => age >= 18);

console.log(adultMember); // { name: 'Alan', age: 20 }

Output

{ name: 'Alan', age: 20 }
{ name: 'Alan', age: 20 }

Recommended Reading: JavaScript Array.findIndex()