Javascript Programming Tutorials, Guides & Best Practices

• Strings: Text, enclosed in quotes ("Hello", 'Hello').
• Numbers: Numerical values (100, 3.14).
• Booleans: True or false values (true, false).
• Arrays: Collections of values ([1, 2, 3]).
• Objects: Key-value pairs ({name: 'John', age: 30}).

Variables store data that can be used and updated later. In JavaScript, you can declare variables using let, const, or var.

Closures are commonly used to create private variables, which are not accessible from outside the function:

function counter() {
    let count = 0;

    return function() {
        count++;
        console.log(count);
    };
}

const increment = counter();
increment();  // Output: 1
increment();  // Output: 2
increment();  // Output: 3