Introduction to JavaScript Basics Quiz

JavaScript is a programming language used to create dynamic content on web pages, allowing for interactive and responsive user experiences.

Variables in JavaScript can be declared using 'let' for mutable variables and 'const' for immutable variables. For example, let name = 'John'; const age = 25;

The syntax for an if statement in JavaScript is 'if (condition) { // code block } else { // code block }'. For example, if (age >= 18) { console.log('You are an adult'); } else { console.log('You are a minor'); }

Functions in JavaScript are declared using the 'function' keyword, and called by using the function name followed by parentheses. For example, function greet(name) { return 'Hello, ' + name + '.'; } let greeting = greet('Alice'); console.log(greeting);

Global variables are declared outside of any function, and can be accessed and modified throughout the program. Local variables are declared within a function and can only be accessed and modified within that function. For example, let globalVar = 'I'm global'; function exampleScope() { let localVar = 'I'm local'; console.log(globalVar); console.log(localVar); } exampleScope();

The three basic data types in JavaScript are: strings (e.g. 'John'), numbers (e.g. 25), and booleans (e.g. true).

Arrays in JavaScript are created using square brackets, and can be manipulated using methods like push() and pop(). For example: let fruits = ['apple', 'orange', 'banana']; fruits.push('grape'); fruits.pop();

The syntax for a for loop in JavaScript is: for (initialization; condition; increment) { // code block }. For example: for (let i = 0; i < 5; i++) { console.log(i); }

In JavaScript, functions have access to variables in their containing scope. For example, a function can access global variables and its own local variables within its scope.

The alert() function in JavaScript is used to display a message in a dialog box. For example: alert('Hello, World.');