Example 1: how to flatten array with reduce in javascript
let flattened = [[0, 1], [2, 3], [4, 5]].reduce(
function(accumulator, currentValue) {
return accumulator.concat(currentValue)
},
[]
)
// flattened is [0, 1, 2, 3, 4, 5]
Example 2: 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 3: javascript reduce sum
let nums = [1, 2, 3];
nums.reduce((curr, next) => curr + next);
Example 4: javascript reduce function
var numbers = [175, 50, 25];
document.getElementById("demo").innerHTML
= numbers.reduce(myFunc);
function myFunc(total, num) {
return total - num;
}
Example 5: reduce javascript
//note idx and sourceArray are optional
const sum = array.reduce((accumulator, element[, idx[, sourceArray]]) => {
//arbitrary example of why idx might be needed
return accumulator + idx * 2 + element
}, 0);
Example 6: javascript, reduce
const myReduce = myArray.reduce((acc, item) => {
acc += item
})