Web Development Concepts Assessment

What is the purpose of a loop in JavaScript?

• The purpose of a loop in JavaScript is to execute code only once

• The purpose of a loop in JavaScript is to repeatedly execute a block of code.

• The purpose of a loop in JavaScript is to stop the code execution

• The purpose of a loop in JavaScript is to skip certain code blocks

How do you declare an array in JavaScript?

• let myArray = [];

• myArray = []

• var myArray = []

• const myArray = []

What is the syntax for creating an object in JavaScript?

• const myObject = { key1: value1, key2: value2 };

• const myObject = ( key1: value1, key2: value2 );

• let myObject = { key1: value1, key2: value2 };

• const myObject = [ key1: value1, key2: value2 ];

Explain the difference between localStorage and sessionStorage in JavaScript.

• localStorage and sessionStorage are the same and can be used interchangeably.

• localStorage persists data even after the browser is closed, while sessionStorage clears data when the browser is closed.

• localStorage clears data when the browser is closed, while sessionStorage persists data even after the browser is closed.

• localStorage and sessionStorage are deprecated in modern browsers.

What is the output of the following loop: for (let i = 0; i < 5; i++) { console.log(i); }

• 0 1 2 3 4

• 5

• 7

• 6

How can you access the third element of an array in JavaScript?

• arrayName.third()

• arrayName(2)

• arrayName[2]

• arrayName[3]

What is the use of the 'this' keyword in JavaScript objects?

• To refer to the current object instance within its own scope.

• To access properties of a different object

• To define a function within the object

• To declare a new variable within the object

How do you store data in localStorage in JavaScript?

• localStorage.saveData('key', 'value')

• localStorage.setItem('key', 'value')

• localStorage.storeData('key', 'value')

• localStorage.addData('key', 'value')

What is the result of the expression: typeof []?

• object

• number

• string

• array

What is the purpose of the 'length' property in JavaScript arrays?

• To reverse the order of elements in the array.

• To determine the number of elements in the array.

• To add a new element to the array.

• To check if a specific element exists in the array.