Test: Variables and Operators - 2

Question 1

Which of the following is true about JavaScript variables?

Accepted Answer

JavaScript variables are case-sensitive.

Answer

Variables must be declared with the "var" keyword.

Answer

Variables must have a data type specified at the time of declaration.

Answer

JavaScript variables cannot be reassigned once they are assigned a value.

Question 2

What is the purpose of the "typeof" operator in JavaScript?

Accepted Answer

To determine the data type of a value stored in a variable.

Answer

To check if a variable has been declared or not.

Answer

To convert a value to a string data type.

Answer

To assign a new data type to a variable.

Question 3

Which of the following is an example of a valid JavaScript variable name?

Accepted Answer

$variable

Answer

my-variable

Answer

123variable

Answer

function

Question 4

What is the result of the following expression: "5" + 2?

Accepted Answer

"52"

Answer

52

Answer

7

Answer

NaN

Question 5

Which of the following is the correct way to declare a constant variable in JavaScript?

Accepted Answer

const x = 5;

Answer

let x = 5;

Answer

var x = 5;

Answer

const x;

Question 6

What is the output of the following code snippet?
var x = 10;
var y = 5;
var z = x + y;
console.log(z);

Accepted Answer

15

Answer

10

Answer

5

Answer

NaN

Question 7

What will be logged to the console by the following code snippet?
var name = "John";
var greeting = "Hello, " + name + "!";
console.log(greeting);

Accepted Answer

Hello, John!

Answer

Hello, name!

Answer

undefined

Answer

Hello, undefined!

Question 8

What is the output of the following code snippet?
var x = 5;
var y = "10";
var z = x + y;
console.log(z);

Accepted Answer

510

Answer

15

Answer

"510"

Answer

NaN

Question 9

What is the result of the following expression: "10" - 5?

Accepted Answer

5

Answer

15

Answer

"105"

Answer

NaN

Question 10

What will be the value of "x" after the following code snippet is executed?
var x = 5;
x += 3;
x *= 2;
console.log(x);

Accepted Answer

16

Answer

5

Answer

8

Answer

11

Question 11

What will be the output of the following code snippet?
var x = 10;
var y = 5;
var z = x > y ? "x is greater" : "y is greater";
console.log(z);

Accepted Answer

x is greater

Answer

y is greater

Answer

10

Answer

5

Question 12

What is the output of the following code snippet?
var x = 5;
var y = "10";
var z = x == y;
console.log(z);

Accepted Answer

true

Answer

false

Answer

10

Answer

NaN

Question 13

What is the value of "result" after the following code snippet is executed?

var a = null;
var b = 5;
var result = a ?? b;
console.log(result);

Accepted Answer

5

Answer

null

Answer

undefined

Answer

0

Question 14

What are the comparison operators in JavaScript used for?

Accepted Answer

To compare values and return a boolean result.

Answer

To perform mathematical calculations.

Answer

To assign values to variables.

Answer

To concatenate strings.

Question 15

What is the purpose of logical operators in JavaScript?

Accepted Answer

To combine or manipulate boolean values and return a boolean result.

Answer

To manipulate date and time.

Answer

To perform string manipulation.

Answer

To create loops and control the flow of program execution.

Variables and Operators - 2 - Free MCQ Practice Test with solutions, Software

MCQ Practice Test & Solutions: Test: Variables and Operators - 2 (15 Questions)

Which of the following is true about JavaScript variables?

What is the purpose of the "typeof" operator in JavaScript?

Which of the following is an example of a valid JavaScript variable name?

What is the result of the following expression: "5" + 2?

Which of the following is the correct way to declare a constant variable in JavaScript?

What is the output of the following code snippet?
var x = 10;
var y = 5;
var z = x + y;
console.log(z);

What will be logged to the console by the following code snippet?
var name = "John";
var greeting = "Hello, " + name + "!";
console.log(greeting);

What is the output of the following code snippet?
var x = 5;
var y = "10";
var z = x + y;
console.log(z);

What is the result of the following expression: "10" - 5?

What will be the value of "x" after the following code snippet is executed?
var x = 5;
x += 3;
x *= 2;
console.log(x);

What will be the output of the following code snippet?
var x = 10;
var y = 5;
var z = x > y ? "x is greater" : "y is greater";
console.log(z);

What is the output of the following code snippet?
var x = 5;
var y = "10";
var z = x == y;
console.log(z);

What is the value of "result" after the following code snippet is executed?
var a = null;
var b = 5;
var result = a ?? b;
console.log(result);

What are the comparison operators in JavaScript used for?

What is the purpose of logical operators in JavaScript?

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Variables and Operators - 2 - Free MCQ Practice Test with solutions, Software

MCQ Practice Test & Solutions: Test: Variables and Operators - 2 (15 Questions)

Which of the following is true about JavaScript variables?

What is the purpose of the "typeof" operator in JavaScript?

Which of the following is an example of a valid JavaScript variable name?

What is the result of the following expression: "5" + 2?

Which of the following is the correct way to declare a constant variable in JavaScript?

What is the output of the following code snippet? var x = 10; var y = 5; var z = x + y; console.log(z);

What will be logged to the console by the following code snippet? var name = "John"; var greeting = "Hello, " + name + "!"; console.log(greeting);

What is the output of the following code snippet? var x = 5; var y = "10"; var z = x + y; console.log(z);

What is the result of the following expression: "10" - 5?

What will be the value of "x" after the following code snippet is executed? var x = 5; x += 3; x *= 2; console.log(x);

What will be the output of the following code snippet? var x = 10; var y = 5; var z = x > y ? "x is greater" : "y is greater"; console.log(z);

What is the output of the following code snippet? var x = 5; var y = "10"; var z = x == y; console.log(z);

What is the value of "result" after the following code snippet is executed?var a = null; var b = 5; var result = a ?? b; console.log(result);

What are the comparison operators in JavaScript used for?

What is the purpose of logical operators in JavaScript?

JavaScript for Web Development

JavaScript for Web Development

Top Courses for Software Development

About this Software Development Practice Test

Explore more Software Development Study Resources

What is the output of the following code snippet?
var x = 10;
var y = 5;
var z = x + y;
console.log(z);

What will be logged to the console by the following code snippet?
var name = "John";
var greeting = "Hello, " + name + "!";
console.log(greeting);

What is the output of the following code snippet?
var x = 5;
var y = "10";
var z = x + y;
console.log(z);

What will be the value of "x" after the following code snippet is executed?
var x = 5;
x += 3;
x *= 2;
console.log(x);

What will be the output of the following code snippet?
var x = 10;
var y = 5;
var z = x > y ? "x is greater" : "y is greater";
console.log(z);

What is the output of the following code snippet?
var x = 5;
var y = "10";
var z = x == y;
console.log(z);

What is the value of "result" after the following code snippet is executed?
var a = null;
var b = 5;
var result = a ?? b;
console.log(result);