Typing lesson: Programming in JavaScript language

JavaScript is one of the most widely used programming languages in the world, powering both client-side and server-side applications. It is a flexible, dynamic language that is constantly evolving. Typing JavaScript code, however, comes with its own challenges. Unlike Python, where whitespace is part of the syntax, or Java, where everything is heavily typed and verbose, JavaScript sits somewhere in the middle: it is permissive, yet full of small syntactic traps. A missing semicolon, an extra comma, or a forgotten parenthesis can break the flow. For developers, especially those who spend hours a day writing code, being proficient with the keyboard is crucial. Touch typing helps minimize careless mistakes, reduces fatigue, and allows programmers to focus on logic rather than the act of pressing keys.

Dynamic typing and variable declarations

JavaScript is dynamically typed, which means variables can hold values of any type and can change type during execution. This flexibility makes the language easy to start with but also error-prone. Declaring variables requires consistent use of let, const, and occasionally var (though var is mostly discouraged). Each of these keywords has different scoping rules. Mistyping them or using the wrong one can lead to subtle bugs. Practicing touch typing makes the use of const and let natural, and helps reinforce the discipline of using the right keyword at the right time.

// Using let for variables that change
let counter = 0;
counter++;

// Using const for immutable bindings
const PI = 3.14159;

// Avoid var in modern code
var legacy = "old style";

Semicolons and automatic insertion

One of the most controversial features of JavaScript is automatic semicolon insertion. Technically, many statements can be written without semicolons, but omitting them can cause strange bugs. A famous example is when a return statement is written on one line and the value on the next line: JavaScript interprets it as return; rather than returning the intended value. For this reason, most style guides recommend always typing semicolons explicitly. For touch typists, this is a small but frequent keystroke, and building the habit of ending lines with semicolons through consistent typing practice prevents elusive runtime errors.

// Dangerous: returns undefined
function bad() {
  return
  {
    name: "Alice"
  };
}

// Safe: semicolon ensures correct return
function good() {
  return {
    name: "Alice"
  };
}

Objects and JSON syntax

JavaScript is built around objects. Writing object literals requires curly braces {}, colons :, and commas , in exactly the right places. JSON, which mirrors JavaScript object syntax, is unforgiving: a trailing comma can make an entire file invalid. For developers who are not comfortable with punctuation, this becomes a constant source of mistakes. Touch typing trains accuracy with these characters. It makes entering braces, colons, and commas automatic, so that the developer's mind can stay on the data structure rather than the keystrokes.

// Object literal
const user = {
  id: 1,
  name: "Alice",
  active: true
};

Functions: declarations, expressions, and arrows

JavaScript offers several ways to define functions: traditional declarations, anonymous expressions, and arrow functions. Arrow functions in particular rely heavily on symbols like =>. For beginners, forgetting a parenthesis or misplacing the arrow is common. A touch typist is more likely to enter these correctly, as the motion of typing => becomes second nature. Furthermore, JavaScript supports default parameters, rest parameters (...args), and destructuring in parameter lists. These add expressive power but also increase the punctuation load while typing.

// Traditional function
function greet(name) {
  return "Hello " + name;
}

// Arrow function
const greetArrow = (name) => "Hello " + name;

// Function with default and rest parameters
function log(message = "Info", ...args) {
  console.log(message, args);
}

Closures and callbacks

One of the defining features of JavaScript is its use of closures. Functions can capture variables from their surrounding scope. This is powerful, but also easy to get wrong, especially when dealing with loops or asynchronous code. Writing callbacks often involves nesting parentheses and braces. Without strong typing skills at the keyboard, it is easy to miss a brace or place a parenthesis in the wrong spot. Touch typing helps make this kind of nested structure easier to manage, as the fingers move predictably over the same sequences of symbols.

// Closure capturing variable
function makeCounter() {
  let count = 0;
  return function() {
    count++;
    return count;
  };
}

const counter = makeCounter();
console.log(counter()); // 1
console.log(counter()); // 2

Asynchronous code: callbacks, promises, async/await

JavaScript was designed for asynchronous operations, and this is reflected in its syntax. Callbacks were the original pattern, but today promises and async/await are more common. Each of these constructs introduces its own typing challenges: nested callbacks require multiple levels of braces, promises use .then() chains, and async/await introduces new keywords. Touch typing is especially helpful here, because writing asynchronous code involves frequent repetition of patterns like try { ... } catch(e) { ... } or await fetch(...). A developer who types accurately will produce clearer, less error-prone asynchronous logic.

// Promise-based
fetch("/api/data")
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(err => console.error(err));

// Async/await
async function loadData() {
  try {
    const response = await fetch("/api/data");
    const data = await response.json();
    console.log(data);
  } catch (err) {
    console.error(err);
  }
}

Style and conventions

While Python programmers talk about being "pythonic," in JavaScript the conversation usually revolves around style guides such as Airbnb, StandardJS, or Google's conventions. These guides cover indentation (two spaces vs four), semicolon usage, naming conventions (camelCase for variables, PascalCase for classes), and even line length. The community expectation is that developers follow a consistent style, enforced by tools like ESLint and Prettier. Typing code consistently according to these conventions is much easier for those who have mastered touch typing, because they can maintain rhythm and precision while writing repetitive patterns such as arrow functions, object keys, or chained method calls.

Common pitfalls in syntax

Some of the most common mistakes when writing JavaScript include forgetting to close template literals (backticks), mixing up single and double quotes, or failing to close brackets. ES6 template strings with embedded expressions ${...} are powerful, but they require a careful sequence of characters: backtick, dollar sign, braces. For a developer who is not confident on the keyboard, this can be tedious. With touch typing, these sequences become routine.

// Template string with interpolation
const name = "Alice";
console.log(`Hello, ${name}!`);

Classes and object-oriented features

Before ES6, JavaScript relied on prototypes for object orientation. Today, classes provide a cleaner syntax, though prototypes still exist under the hood. Writing classes requires the use of constructor, super, and method definitions without the function keyword. Misplacing braces or forgetting this are common mistakes. With touch typing, writing these repetitive patterns is smoother and less error-prone. As in Java, classes in JavaScript often follow PascalCase naming conventions, which also benefit from consistent keyboard habits.

class Animal {
  constructor(name) {
    this.name = name;
  }
  speak() {
    console.log(`${this.name} makes a noise.`);
  }
}

class Dog extends Animal {
  speak() {
    console.log(`${this.name} barks.`);
  }
}

Modules and imports

Modern JavaScript uses ES modules, with import and export statements. These often involve long paths and curly braces. Writing import { readFile, writeFile } from "fs"; quickly and accurately is not trivial for beginners. Again, practicing with touch typing builds muscle memory for braces and quotes, which reduces friction when working with modules.

import { readFile, writeFile } from "fs";
import express from "express";

Summary

JavaScript is a dynamic, flexible, and expressive language. Its syntax combines a wide range of symbols - braces, brackets, colons, commas, semicolons, backticks - and this makes typing it accurately a constant challenge. Unlike Java, it is not verbose, but it is full of small traps where a missing symbol can break execution. Unlike Python, it does not enforce indentation, but consistent formatting is expected by the community. Touch typing helps developers navigate all of this: it reduces errors with punctuation, makes repetitive patterns like arrow functions or imports easier to enter, and allows focus to remain on program design rather than the keyboard. For those who spend hours each day coding in JavaScript, mastering the skill of touch typing is not just about speed - it is about clarity, confidence, and writing code that works the first time.