What keyword is used in pseudocode to represent a loop with a condition at its beginning?

The WHILE keyword represents a pre-condition loop — one that checks a condition at the beginning before each iteration. The syntax is: WHILE condition DO ... ENDWHILE. If the condition is FALSE initially, the loop body never executes.

What is the difference between a pre-condition and post-condition loop in pseudocode?

A pre-condition loop (WHILE...ENDWHILE) checks the condition BEFORE each iteration — the body may never run. A post-condition loop (REPEAT...UNTIL) checks AFTER each iteration — the body always runs at least once. WHILE loops are condition-controlled indefinite iteration; REPEAT UNTIL loops are also indefinite but guaranteed to execute once.

What is definite iteration in pseudocode?

Definite iteration (also called count-controlled iteration) uses a FOR loop that repeats a set number of times. The syntax is: FOR counter ← start TO end ... NEXT counter. You know exactly how many times the loop will run before it starts.

How do you write a REPEAT UNTIL loop in pseudocode?

The syntax is: REPEAT followed by the loop body, then UNTIL condition. For example: REPEAT OUTPUT 'Enter a positive number' INPUT num UNTIL num > 0. The loop keeps repeating UNTIL the condition becomes TRUE.

Finding Max, Min, Counting & Totaling

Quick Reference:

Counting - Incrementing a variable to keep track of occurrences.
Totaling - Accumulating a running sum of values.
Finding Max & Min - Storing the largest or smallest value seen so far.

Counting

Counting is used to find out how many times an event occurs or how many items meet a certain condition. You always initialize the count to 0 before the loop, and increment it by 1 inside the loop.

Hover to Reveal Example

DECLARE Count : INTEGER
DECLARE LoopIndex : INTEGER
DECLARE UserInput : INTEGER

Count ← 0

FOR LoopIndex ← 1 TO 5
    OUTPUT "Enter a number: "
    INPUT UserInput
    IF UserInput > 10 THEN
        Count ← Count + 1
    ENDIF
NEXT LoopIndex

OUTPUT "You entered ", Count, " numbers greater than 10."

Totaling

Totaling (or accumulating) keeps a running sum. Initialize the total to 0 before the loop, and add the current value to it inside the loop.

Hover to Reveal Example

DECLARE Total : INTEGER
DECLARE LoopIndex : INTEGER
DECLARE UserInput : INTEGER

Total ← 0

FOR LoopIndex ← 1 TO 3
    OUTPUT "Enter a price: "
    INPUT UserInput
    Total ← Total + UserInput
NEXT LoopIndex

OUTPUT "The total price is: ", Total

Finding Maximum and Minimum

To find the largest or smallest value in a sequence, you need a variable to store the "best seen so far". You can initialize the Max and Min variables in two ways:

Method 1: First Input - Read the first value outside the loop and set it as both Max and Min. This is the safest method.
Method 2: Extreme Values - Initialize Max to a very small number (e.g. -9999) and Min to a very large number (e.g. 9999).

Hover to Reveal Example

DECLARE MaxValue : INTEGER
DECLARE MinValue : INTEGER
DECLARE CurrentNum : INTEGER
DECLARE LoopIndex : INTEGER

// Initialize with the first input
OUTPUT "Enter number 1: "
INPUT CurrentNum
MaxValue ← CurrentNum
MinValue ← CurrentNum

// Loop for the remaining numbers
FOR LoopIndex ← 2 TO 5
    OUTPUT "Enter number ", LoopIndex, ": "
    INPUT CurrentNum
    
    IF CurrentNum > MaxValue THEN
        MaxValue ← CurrentNum
    ENDIF
    
    IF CurrentNum < MinValue THEN
        MinValue ← CurrentNum
    ENDIF
NEXT LoopIndex

OUTPUT "Maximum: ", MaxValue
OUTPUT "Minimum: ", MinValue

Max, Min, Counting & Totaling

Counting

Totaling

Finding Maximum and Minimum

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