Learning JavaScript Data Structures and Algorithms - Third Edition

Functional versus imperative programming

Developing in the functional paradigm is not difficult; it is just a matter of getting used to how the paradigm works. Let's code an example to note the differences.

Consider that we need to print all the elements of an array. We can use imperative programming and declare the following function:

const printArray = function(array) { 
  for (var i = 0; i < array.length; i++){ 
    console.log(array[i]); 
  } 
}; 
printArray([1, 2, 3, 4, 5]); 

In the preceding code, we iterated the array and logged each of the items.

Now, let's try converting the example to functional programming. In functional programming, the functions are the rock stars. We need to focus on what needs to be described, not how. Let's go back to ...