JavaScript array map(), find() and reduce() example

The map() method creates a new array by applying a provided function on every element in the calling array.
The find() method returns the value of the first element that satisfies the provided function; otherwise undefined is returned.
The reduce() method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value.
Check out all 100 + JavaScript Examples
Check out all JavaScript programs at All JavaScript Programs 

JavaScript array map

The map() method creates a new array by applying a provided function on every element in the calling array.
const a1 = ['dog', 'tree', 'smart'];

const a2 = a1.map(e => e.toUpperCase());
console.log(a2);
We have an array of words. With the map() method, we apply the toUpperCase() method on each of the words.
This is the output:
[ 'DOG', 'TREE', 'SMART' ]

JavaScript array find

The find() method returns the value of the first element that satisfies the provided function; otherwise undefined is returned.
const nums = [2, -3, 4, 6, 1, 23, 9, 7];

const e1 = nums.find(e => e > 10);
console.log(e1);
In the example, we print the first value that is greater than 10.
This is the output:
23

JavaScript array reduction

The reduce() method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value.
const nums = [2, 3, 4, 5, 6, 7];

const res = nums.reduce((product, next) => product * next);

console.log(res);
This is the output:
5040
Check out all 100 + JavaScript Examples
Check out all JavaScript programs at All JavaScript Programs 

Comments