What is the use of js reduce method in web front end

What is the use of the js reduce method in the front end of web? I believe many inexperienced people are at a loss about it. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

The web front-end tutorials share the js reduce method using the tutorials, and the reduce () method takes a function as an accumulator, and each value in the array (from left to right) starts to shrink and eventually evaluates to a value.

Reduce () can be used as a higher-order function for the compose of a function.

Syntax:

Array.reduce (total, currentValue, currentIndex, arr), initialValue)

Parameters:

Total is required. The initial value, or the return value after the calculation is finished.

CurrentValue is required. Current element

CurrentIndex is optional. Index of the current element

Arr is optional. The array object to which the current element belongs.

InitialValue is optional. The initial value passed to the function

Example: