javascript sum array reduce code example

Example 1: sum of number using reduce

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

Example 2: javascript reduce sum

arrSum = function(arr){  return arr.reduce(function(a,b){    return a + b  }, 0);}

Example 3: syntax of reduce in js

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

Example 4: 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);