First look into JavaScript

      I have been learning and coding with Java for a year, and it is also my first programming language that I have learned. Heading into my third semester as a Computer Science major, my ICS 314 (Software Engineering) course uses Javascript instead of Java. After reading into Javascript, these are my thoughts and worries on Javascript.

Behavior

Weakly Typed

      The most immediate difference between Javascript and Java is the declaration of variables. Instead of declaring variables with their explicit type, Javascript simply uses let and const followed by a variable. That got me immediately thinking, “how do I exactly know what is the type of a certain variable?”

Instead of having to explicitly declare the type of the variable like in Java,

  int foo = 0;
  String str = "Hello";

      I learned that Javascript is what is called a “dynamic typed” and “weakly typed” language. It means that Javascript doesn’t enforce the correct type. It could care less if you pass just the variable arr as an argument into a function, even if that arr is supposed to take an array as the argument. For example,

function test(arr) {
  arr[0] = "Hello World!";
  return arr[0];
}

      In the code snippet above, we simply passed arr as a parameter for the test function. But if we take a look at what the function is doing, then we can see clearly that arr is suppose to be an array based off of the second line. However, it seems like Javascript doesn’t seem to care. It just magically seems to know that arr is supposed to be a variable that holds an array based on how we inserted the string “Hello World” into the 0th index of arr. The part that worries me the most when it comes to this “weakly typed” language is that it could possibly be harder to debug code if I don’t explicitly know what the type an object is right away.

Classes

      Another difference that I learned when it comes to Javascript is that it uses an object-oriented programming style called prototypal OO. In Java, there is a distinct difference between a Class and an object. A Class is the blueprint that creates objects, which are instances of a Class, that contain the object’s behavior and states. However, in JavaScript, there seems to be no distinct difference between a Class and an object. Classes themselves are also considered objects.

Functional Programming

      One particular thing that I am interested about when it comes to Javascript is functional programming. We all know that Java is an OOP language which primarily uses objects to model real world things. But what if the program that I want to code doesn’t need to be modeled after a real world object? In particular, what if I don’t want my objects and their properties to be constantly changing all over the place. I believe that is when functional programming comes into play. With my limited knowledge of the subject, I think functional programming aims to have functions rather than objects as the building blocks for a program.

      Rather than modifying the objects themselves, the objects are passed around functions and those functions do the work instead. Functional programming heavily emphasizes on avoiding changing states and working with mutable data.

      Overall, I am excited to expand my skillset through learning Javascript. Although Javascript isn’t just limited to web development, I have heard that there could be better programming languages than Javascript if I were to use it for non-web development use. Regardless, being able to build a web app through Javascript would be an important skill to have. In the future, I do plan on building websites for my own personal use; therefore, learning Javascript is an excellent way to start.