Understanding Pseudo Code

Pseudo Code

• Pseudo code uses English keywords to represent algorithms, similar to high-level programming languages like Python.
• Meaningful names are given to data items, like variables and constants in programming.
• It is not bound by strict syntax rules.
• The arrow symbol (<-) is used to assign values to variables or constants, like the equals sign in programming.

Mathematical Operators

• Plus sign (+) is used for addition.
• Minus sign (-) is used for subtraction.
• Star (*) is used for multiplication
• Slash (/) is used for division.
• Up arrow (^) is used to raise to the power.
• Parentheses/brackets () are used to define order of operations.

Conditional Statements: IF

• Conditional statements can be true or false
• Structure: IF condition THEN action ENDIF
• IF variable age < 18 THEN print "child" ELSE print "adult" ENDIF

Conditional Statements: CASE

• Used for choosing items from a list.
• Structure: CASE variable OF option1: action1 option2: action2 OTHERWISE: default action ENDCASE
• Example: CASE grade OF A: print "excellent" B: print "good" C: print "average" OTHERWISE: print "improvement needed" ENDCASE

Comparison Operators

• Greater than (>)
• Less than (<)
• Equal to (=)
• Greater than or equal to (>=)
• Less than or equal to (<=)
• Not equal to (!=)
• AND, OR, NOT for combining conditions

Nested IFs

• An IF statement inside another IF statement.

Loops: FOR Loop

• Use "FOR" to repeat an action a specific number of times
• Example: FOR counter <- 1 TO 10 DO output star NEXT counter (prints 10 stars)

Loops: REPEAT UNTIL Loop

• "REPEAT" an action UNTIL a condition is met
• Example:
  • counter <- 0
  • REPEAT output star
  • counter <- counter + 1
  • UNTIL counter > 9

Loops: WHILE Loop

• "WHILE" a condition is true, DO an action
• Example:
  • counter <- 0
  • WHILE counter < 10 DO
  • output star counter <- counter + 1
  • ENDWHILE
• Can have preconditioned loops (test at the beginning) or post-conditioned loops.

Input and Output

• OUTPUT displays a message on the screen.
• INPUT gets a value from the user.

Editors

• Sample pseudo code can be tested using online editors.