Pseudocode Sandbox

Write and run pseudocode to see how algorithms execute step-by-step. Watch the trace table update as your code runs!

Interactive Pseudocode Runner

Write pseudocode and see how it executes step-by-step

Code

Output

Output will appear here...

Trace Table

Run code to see trace table...

Syntax Reference

Variables

x = 5name = "Alice"

Output

OUTPUT xOUTPUT "Hello"

FOR Loop

FOR i = 1 TO 5 OUTPUT iNEXT i

WHILE Loop

WHILE x < 10 x = x + 1ENDWHILE

IF Statement

IF x > 5 THEN OUTPUT "Big"ELSE OUTPUT "Small"ENDIF

Operators

+ - * / MOD= <> < > <= >=AND OR NOT

Try These Examples

Sum 1 to 10:

total = 0
FOR i = 1 TO 10
    total = total + i
NEXT i
OUTPUT total

Even or Odd:

num = 7
IF num MOD 2 = 0 THEN
    OUTPUT "Even"
ELSE
    OUTPUT "Odd"
ENDIF

Countdown:

n = 5
WHILE n > 0
    OUTPUT n
    n = n - 1
ENDWHILE
OUTPUT "Blast off!"

Understanding Trace Tables

A trace table shows the values of variables at each step of program execution. They're essential for:

✓ Desk checking - manually testing your algorithm
✓ Finding errors - spotting where logic goes wrong
✓ Understanding loops - seeing how variables change each iteration
✓ Exam preparation - trace tables are commonly assessed!

Learn more about testing & debugging →

Exam Tip

When completing trace tables in exams, always show the initial value of each variable and update the table every time a variable changes. Don't skip iterations in loops - markers want to see each step clearly documented.

← Interactive Exercises Trace Table Worksheets