Javascript H446 OCR Quiz

What are the different data types in JavaScript?

• cat, dog, bird, fish

• apple, banana, orange, grape

• red, blue, green, yellow

• string, number, boolean, object, function, undefined, and null

How do you declare a variable in JavaScript?

• declare followed by the variable name

• function followed by the variable name

• var, let, or const followed by the variable name

• variable followed by the variable name

What is the difference between let, var, and const in JavaScript?

• The 'let' keyword is used to declare a block-scoped variable, the 'var' keyword is used to declare a function-scoped variable, and the 'const' keyword is used to declare a constant variable.

• The 'var' keyword is used to declare a block-scoped variable

• The 'let' keyword is used to declare a function-scoped variable

• The 'const' keyword is used to declare a variable that can be reassigned

Explain the concept of scope in JavaScript.

• Scope in JavaScript is related to the speed at which the code is executed

• The concept of scope in JavaScript refers to the color scheme used in the code

• Scope in JavaScript refers to the process of organizing code into separate files

• The concept of scope in JavaScript refers to the visibility and accessibility of variables and functions within a particular part of the code.

What is a function in JavaScript?

• A block of code that can be defined and then called or invoked to perform a particular task.

• A form of conditional statement in JavaScript

• A type of variable in JavaScript

• A built-in object in JavaScript

What is event handling in JavaScript?

• Event handling in JavaScript is the process of debugging events

• Event handling in JavaScript is the process of creating new events

• Event handling in JavaScript is the process of capturing and responding to events such as user actions or system events.

• Event handling in JavaScript is the process of styling events

How do you add an event listener in JavaScript?

• attachEventListener

• createEventListener

• addEventListenerListener

• addEventListener

Explain the concept of event bubbling in JavaScript.

• Event bubbling is the act of canceling an event before it reaches the target element in the DOM.

• Event bubbling is the propagation of an event from the target element up to its parent elements in the DOM.

• Event bubbling is the process of deflating an event from the parent element down to its child elements in the DOM.

• Event bubbling is the movement of an event in a circular pattern within the same element in the DOM.

What is the difference between event.preventDefault() and event.stopPropagation() in JavaScript?

• event.stopDefault() is used to stop the event from happening at all

• event.preventDefault() is used to prevent the default behavior of an event, while event.stopPropagation() is used to stop the event from bubbling up the DOM tree.

• event.stopPropagation() is used to prevent the event from being triggered

• event.preventDefault() is used to stop the event from propagating to child elements