Javascript I

What keyword is used to declare a variable in JavaScript?

• let

• var

• const

What is hoisting in JavaScript?

• It's a JavaScript engine's way of moving all variable declarations to the top of the function or global scope.

• It's a way to make variables float in the air.

• It's a form of error handling.

• It's related to the event handling mechanism.

What is the key difference between using let and var to declare variables in JavaScript?

• • let variables have block scope, while var variables have function scope.

• var variables have block scope, while let variables have function scope.

• There is no difference between let and var in terms of scoping.

• let variables are global, while var variables are local.

Which JavaScript method is used to add a new HTML element to the DOM?

• appendNode()

• createElement()

• addHTML()

• appendChild()

What is the purpose of the typeof operator in JavaScript?

• To check the type of a variable or expression.

• To perform mathematical operations.

• To create arrow functions.

• To compare two values for equality.

Which JavaScript event occurs when a user clicks on an HTML element?

• hover

• load

• click

• submit

What is a regular expression (RegEx) in JavaScript used for?

• To format design pattern.

• To create text.

• To search for and manipulate patterns in strings.

A variable;

• Expresses a true false statement
  
• stores a string, number, or boolean, and gives it a specific, case-sensitive name
  
• takes in an input, does something with it, and then returns an output.
  
• Runs a boolean (true/false) statement based on data entered
  

A boolean;

• Expresses a true false statement
  
• can contain letters, numbers, spaces, and symbols.
  
• takes in an input, does something with it, and then returns an output.
  
• Runs a boolean (true/false) statement based on data entered
  

What will be the output of this code?

• Hi there
  Goodbye

• Ciao!
  Goodbye

• Ciao!
  ReferenceError: wariable not defined.