CodingHowTo

Using the `let` Keyword

The `let` keyword is used to declare variables that can be reassigned later. Here's an example:

let greeting = "Hello, World!";
console.log(greeting); // Output: Hello, World!

Using the `const` Keyword

The `const` keyword is used to declare variables that cannot be reassigned. They must be initialized at the time of declaration:

const pi = 3.14;
console.log(pi); // Output: 3.14

Using the `var` Keyword (Legacy)

The `var` keyword is an older way to declare variables. It's less commonly used today due to differences in scope and potential issues with variable hoisting:

var message = "Welcome!";
console.log(message); // Output: Welcome!

Initializing Multiple Variables

You can declare and initialize multiple variables in a single line using commas:

let firstName = "John", lastName = "Doe";
console.log(firstName + " " + lastName); // Output: John Doe

Initializing Variables Without a Value

You can declare variables without immediately assigning them a value. They will be initialized with `undefined`:

let age;
console.log(age); // Output: undefined

Conclusion

Declaring and initializing variables is a fundamental skill in JavaScript. Using `let` for reassignable values, `const` for constants, and understanding the legacy `var`, you can effectively manage data within your programs. As you continue to learn JavaScript, remember that proper variable declaration and initialization are key to writing clean and efficient code.