Free Practice Quiz Question List

3 Conditionals and Boolean Logic Online Quiz Questions

Use this free practice quiz with 20 questions to review 3 Conditionals and Boolean Logic, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

True or false: In JavaScript, an empty array is truthy when it is evaluated as the condition of an if statement.

A
True
B
False

Choose one

1 point

Which JavaScript expression evaluates to true because it allows type conversion between a number and a string?

A
5 === "5"
B
5 == "5"
C
5 !== "5"
D
5 === 5

Fill in the blank

1 point

Complete the statement: To require that a customer is a member has spent at least $50, combine the two conditions with the JavaScript operator shown in the blank.

Written response

1 point

What JavaScript term describes a non-Boolean value that behaves like true when used as an if condition?

Choose one

1 point

Given const user = null;, what happens in if (user && user.name) { ... }?

A
It throws an error while evaluating user.name.
B
It skips evaluating user.name.
C
It changes user into an empty object.
D
It evaluates user.name and returns undefined.

True or false

1 point

True or false: If a program checks age >= 18 before age >= 65 in an else if chain, the senior branch can still run for an age of 70.

A
True
B
False

Fill in the blank

1 point

Complete the statement: The JavaScript operator that reverses a Boolean condition is .

Choose all

1 point

Which values are falsy in JavaScript? Select all correct choices.

A
0
B
""
C
null
D
undefined
E
NaN
F
[]

Written response

1 point

What string is assigned to displayName by this code? const enteredName = ""; const displayName = enteredName || "Guest";

Choose one

1 point

Which JavaScript condition correctly implements this rule: a discount applies when a customer is a member who spends at least $50, or when the customer has a promotional code?

A
(isMember && purchaseTotal >= 50) || hasPromoCode
B
isMember || purchaseTotal >= 50 || hasPromoCode
C
isMember && (purchaseTotal >= 50 || hasPromoCode)
D
(isMember || purchaseTotal >= 50) && hasPromoCode

Choose all

1 point

Which practices help make JavaScript conditional logic clearer or less error-prone? Select all correct choices.

A
Prefer === and !== for comparisons by default.
B
Use braces around conditional branches.
C
Test values just below, exactly at, and just above a limit.
D
Use score = 10 when you need to test whether score equals 10.

Open ended

1 point

Explain a reliable process for designing and checking a JavaScript conditional that has multiple requirements and boundary values. Include one correctly grouped Boolean expression as an example.

Choose one

1 point

What does this code print when age is 70?

if (age >= 65) { console.log("Senior"); } else if (age >= 18) { console.log("Adult"); } else { console.log("Minor"); }

A
It prints Minor.
B
It prints Adult.
C
It prints Senior.
D
It prints nothing because both conditions are true.

Choose one

1 point

Which value is truthy in JavaScript?

A
0
B
""
C
[]
D
null

True or false

1 point

True or false: In JavaScript, user && user.name safely avoids attempting to read name when user is null.

A
True
B
False

Choose one

1 point

What is the result of the JavaScript expression 18 === "18"?

A
true
B
false
C
It throws an error
D
It returns the string "false"

Written response

1 point

Which JavaScript logical operator requires both conditions to be true?

Choose one

1 point

Given isMember = true, purchaseTotal = 35, and hasPromoCode = false, what is the value of (isMember && purchaseTotal >= 50) || hasPromoCode?

A
true
B
false
C
It evaluates to the purchase total, 35
D
It evaluates to the string "No"

Choose one

1 point

Which if...else if...else chain correctly labels a person who is 65 or older as Senior, a person aged 18 through 64 as Adult, and anyone younger than 18 as Minor?

A
if (age >= 65) { console.log("Senior"); } else if (age >= 18) { console.log("Adult"); } else { console.log("Minor"); }
B
if (age >= 18) { console.log("Adult"); } else if (age >= 65) { console.log("Senior"); } else { console.log("Minor"); }
C
if (age < 18) { console.log("Minor"); } else if (age < 65) { console.log("Senior"); } else { console.log("Adult"); }
D
if (age >= 65) { console.log("Adult"); } else if (age >= 18) { console.log("Senior"); } else { console.log("Minor"); }

Written response

1 point

Which JavaScript operator assigns a fallback only when the left operand is null or undefined?