Program Flow

Question 1

What’s the flow of a program?

Answer 1

The order that the steps are carried out in.

Question 2

How can you control the program flow?

Answer 2

Using selection statements: IF statements and CASE statements.

Question 3

What is an IF statement?

Answer 3

Allows you to check if a condition is true or false, and carry out different actions depending on the outcome.

Question 4

What is a nested IF statement?

Answer 4

Putting another IF statement inside another.

Question 5

What does a nested IF statement allow?

Answer 5

• check more conditions once you’ve established the previous condition is true.

Question 6

What is IF-ELSEIF statement?

Answer 6

Used to check multiple conditions. They’re different from nested IF statements as they only check more conditions if the previous condition is false.

Question 7

What is a SWITCH-CASE statement?

Answer 7

Instead of checking if a statement is true or false, it checks if a variable has specific values.

Question 8

What are SWITCH-CASE statements used for?

Answer 8

When you want a program to perform different actions for different values of the same variable.

Question 9

How are SWITCH-CASE statements different to IF statements?

Answer 9

They have a smilier structure but SWITCH-CASE statements give a neater way to test different values of a variable, this makes them easier than ELSEIF statements to maintain.

Question 10

What is a disadvantage of SWITCH-CASE statements?

Answer 10

They can only check the value of one variable.

Question 11

What is a FOR loop?

Answer 11

It’ll repeat the code inside a fixed number of times. The number of times that the code repeats will depend on an initial value, end value and the step count.

Question 12

What makes SWITCH-CASE statements more robust?

Answer 12

They include a ‘default’ case which tells the program what to do if none of the other cases are correct.

Question 13

What are DO UNTIL loops?

Answer 13

• controlled by a condition at the end of the loop.
• keep going until the condition is true (i.e. while it’s false)
• always run the code inside them at least once
• you get an infinite loop if the condition is never true

Question 14

What are WHILE loops?

Answer 14

• controlled by a condition at the start of the loop
• keep going while the condition is true (i.e. until it’s false)
• never run the code inside them if the condition is initially false
• you get an infinite loop is the condition is always true.

Question 15

What are DO WHILE loops?

Answer 15

• controlled by a condition at the end of the loop
• keep going while the condition is true (i.e. until it’s false)
• always run the code inside them at least once.
• you get an infinite loop if the condition is always true.