JavaScript Fundamentals for Beginners

What is a variable in JavaScript?

• A variable in JavaScript is a named container for storing data values.

• A variable in JavaScript is a method for defining classes.

• A variable in JavaScript is a type of loop used for iteration.

• A variable in JavaScript is a function that performs calculations.

Which of the following is a valid way to declare a variable?

• let x = 5;

• const x = 5;

• var x = 5;

• x := 5;

What data type is used to represent true or false values?

• boolean

• float

• string

• integer

What is the result of the expression 5 + '5'?

• 5 + 5

• 55.0

• 55

• 10

How do you create a function in JavaScript?

• function myFunction(param1, param2) { // function body } or const myFunction = (param1, param2) => { // function body }

• createFunction(param1, param2) { // function body }

• myFunction: function(param1, param2) { // function body }

• function myFunction(param1, param2) => { // function body }

What is the scope of a variable declared with 'let'?

• Function scope

• Global scope

• Module scope

• Block scope

What is the purpose of the 'return' statement in a function?

• To create a loop within the function.

• To end the function execution immediately.

• To define the function's parameters.

• The purpose of the 'return' statement is to provide a value from a function to its caller.

How can you access the first element of an array?

• The first element can be retrieved using arrayName.get(0).

• Use arrayName[1] to access the first element of an array.

• Access the first element with arrayName.first() method.

• Use arrayName[0] to access the first element of an array.

What is the difference between '==' and '===' in JavaScript?

• Both '==' and '===' check for strict equality.

• '==' and '===' are interchangeable operators.

• The difference is that '==' performs type coercion while '===' does not.

• '==' is faster than '===' in execution.

How do you create an object in JavaScript?

• You can create an object in JavaScript using: `let obj = {}`.

• You create an object by declaring a variable with `var obj;`

• Objects can only be created with classes in JavaScript.

• You can create an object using `let obj = new Object();`