Reduce method

Javascript reduce

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

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

Javascript sum array values

function getArraySum(a){
    var total=0;
    for(var i in a) { 
        total += a[i];
    }
    return total;
}

var payChecks = [123,155,134, 205, 105]; 
var weeklyPay= getArraySum(payChecks); //sums up to 722

Js reduce

// syntax: array.reduce(function, accumulator-initial-value)
let array = [3, 7, 2, 9, 5]
const result = array.reduce((accumulator, currentValue, currentIndex, arr) => {
  // code
}, initialValue)

// accumulator = will store return value of the function
// currentValue = iterate through each array element
// currentIndex = index of currentValue
// arr = original array
// initialValue = set accumulator initial value

Source: developer.mozilla.org

Reduce

// Array.prototype.reduce()

const array1 = [1, 2, 3, 4];
const reducer = (accumulator, currentValue) => accumulator + currentValue;

// 1 + 2 + 3 + 4
console.log(array1.reduce(reducer));
// expected output: 10

// 5 + 1 + 2 + 3 + 4
console.log(array1.reduce(reducer, 5));
// expected output: 15

Reduce method

The reduce() method executes a reducer function (that you provide) on each element of the array, resulting in single output value.

The reducer function takes four arguments:
Accumulator (acc)
Current Value (cur)
Current Index (idx)
Source Array (src)

//syntax
arr.reduce(callback( accumulator, currentValue, [, index[, array]] )[, initialValue])
//example flatten an array

let flattened = [[0, 1], [2, 3], [4, 5]].reduce(
  ( accumulator, currentValue ) => accumulator.concat(currentValue),
  []
)

Source: developer.mozilla.org

Reduce method

function reduce(array, combine, start) {
  let current = start;
  for (let element of array) {
    current = combine(current, element);
  }
  return current;
}

console.log(reduce([1, 2, 3, 4], (a, b) => a + b, 0));
// → 10

Source: eloquentjavascript.net

Similar codes

42 votes111 views5 answers
Npm bootstrap
CSS
37 votes113 views3 answers
Inline svg css
CSS
0 vote119 views1 answer
Siteorigin hide row
CSS
1 vote109 views1 answer
Input date icon width
CSS
76 votes118 views6 answers
Border radius css
CSS
0 vote158 views1 answer
Shopify display flex not working
CSS
98 votes133 views2 answers
Css box-shadow shorthand
CSS
19 votes72 views2 answers
Add font to react
CSS
7 votes114 views2 answers
Css font families
CSS
0 vote117 views1 answer
Css file not getting captured in laravel project
CSS