reduce() method in es6 code example
Example 1: 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 2: reduce javascript
function reduce(array, func, seed) {
let previousResult;
if (seed === undefined) {
previousResult = array[0];
for (let i = 1; i < array.length; i++) {
previousResult = func(previousResult, array[i], i, array);
}
console.log(previousResult);
} else {
previousResult = seed;
each(array, function(e, i, a) {
previousResult = func(previousResult, e, i, array);
});
}
return previousResult;
};