Boolean Logic, Comparison Operators, and Loops Review Quiz

Complete the statement: The else block in an if-else statement is executed when ______.

• A) All conditions are true

• B) No conditions are true

• C) The first condition is true

• D) The last condition is true

Answer explanation

The else block in an if-else statement is executed when no conditions are true. This means that if all preceding if conditions fail, the else block will run, making option B the correct choice.

Anika is filling water bottles. She starts with 0 bottles and continues to fill one bottle at a time until she has filled 5 bottles. When does she stop filling bottles?

• When she has filled 5 bottles

• When she has filled 4 bottles

• When she has filled 6 bottles

• When she has filled 3 bottles

Answer explanation

Anika stops filling bottles when she has filled 5 bottles, as that is her goal. Therefore, the correct answer is when she has filled 5 bottles.

Michael and Harper are planning a picnic. They will go only if both the weather is sunny and they both have a day off. What does the && (AND) operator return when both conditions are true?

• true

• false

• undefined

• an error

Answer explanation

The && (AND) operator returns true when both conditions are true. Since Michael and Harper will picnic only if the weather is sunny and they both have a day off, both conditions being true results in true.

Zoe is deciding whether to go for a walk. She will only go if it is sunny and not raining. What is the result of it being sunny && raining?

• She will go for a walk

• She will not go for a walk

• undefined

• an error

Answer explanation

Zoe will not go for a walk because the condition requires it to be sunny and not raining. Since it is raining, the condition is not met.

What is the output of the following code? let i = 0;

while (i < 4) {

console.log(i);

i++;

}

• A) 0 1 2 3

• B) 1 2 3 4

• C) 0 1 2 3 4

• D) 2 3 4 5

Answer explanation

The code initializes i to 0 and enters a while loop that runs as long as i is less than 4. It logs the value of i and increments it. The output will be 0, 1, 2, and 3, making the correct answer A) 0 1 2 3.

Fill in the blank: Henry uses a for loop to ____ when he wants to practice his guitar scales a specific number of times each day.

• Repeat a block of code a specific number of times

• Execute code only once

• Check conditions

• Handle exceptions

Answer explanation

Henry uses a for loop to repeat a block of code a specific number of times, which is ideal for practicing guitar scales daily. The other options do not align with the purpose of a for loop.

What is the output of the following code? let i = 0;

while (i < 3) {

console.log(i);

i++;

}

• A) 0 1 2

• B) 1 2 3

• C) 0 1 2 3

• D) 2 3 4

Answer explanation

The code initializes i to 0 and enters a while loop that runs as long as i is less than 3. It logs the value of i and increments it. The output will be 0, 1, and 2, making the correct answer A) 0 1 2.

What is the output of the following JavaScript code? let x = 10; console.log(x != 10);

• true

• false

• 10

• error

Answer explanation

The code checks if x (10) is not equal to 10 using the '!=' operator. Since 10 is equal to 10, the expression evaluates to false. Therefore, the output is false.

What is the purpose of an else statement?

• A) To execute code only if the condition is true

• B) To execute code only if the condition is false

• C) To break out of a loop

• D) To restart the program

Answer explanation

The else statement is used to execute code when the preceding condition is false. Therefore, the correct choice is B) To execute code only if the condition is false.

What is the output of the following code? let num = 5;

if (num < 10) {

console.log("Less");

} else if (num == 10) {

console.log("Equal");

} else {

console.log("More");

}

• Less

• Equal

• More

• Error

Answer explanation

The variable 'num' is set to 5. The first condition checks if 'num' is less than 10, which is true. Therefore, it executes 'console.log("Less")', resulting in the output 'Less'.