.reduce() javascript code example

Example 1: javascript sum of array

const sum = arr => arr.reduce((a, b) => a + b, 0);

Example 2: javascript reduce

var array = [36, 25, 6, 15];

array.reduce(function(accumulator, currentValue) {
  return accumulator + currentValue;
}, 0); // 36 + 25 + 6 + 15 = 82

Example 3: reduce javascript

const sum = array.reduce((accumulator, element) => {
  return accumulator + element;
}, 0);
// An example that will loop through an array adding
// each element to an accumulator and returning it
// The 0 at the end initializes accumulator to start at 0
// If array is [2, 4, 6], the returned value in sum
// will be 12 (0 + 2 + 4 + 6)

const product = array.reduce((accumulator, element) => {
  return accumulator * element;
}, 1);
// Multiply all elements in array and return the total
// Initialize accumulator to start at 1
// If array is [2, 4, 6], the returned value in product
// will be 48 (1 * 2 * 4 * 6)

Example 4: reduce javascript

let sum = arr.reduce((curr, index) => curr + index);

Example 5: syntax of reduce in js

[1,2,3,4,5].reduce((acc, current)=>acc+current, 0)

Example 6: javascript reduce function

var numbers = [175, 50, 25];

document.getElementById("demo").innerHTML 
  = numbers.reduce(myFunc);

function myFunc(total, num) {
  
  return total - num;
}