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: javascript reduce
var array = [36, 25, 6, 15];
array.reduce(function(accumulator, currentValue) {
return accumulator + currentValue;
}, 0); // 36 + 25 + 6 + 15 = 82
Example 3: 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
Example 4: js reduce
Sum array elements:
let myArr = [1,2,3,-1,-34,0]
return myArr.reduce((a,b) => a + b,0)
Example 5: .reduce mdn
arr.reduce(callback( accumulator, currentValue[, index[, array]] )[, initialValue])
Example 6: 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);