★ constructs

☆ for loops

a loop, also called iteration or repetition, is a way to repeat one or more statements

a for loop executes the code inside for a specified amount of times

• the variable name can be whatever you want (eg. count)
• the start value is the number the variable starts counts from
• the end value is the number the variable stops counting at
• auto-increment: when the value increases by itself, in this case, the variable

FOR variable name FROM start number TO end number
END FOR

pseudocode example: displays every even number from 1 to n

RECEIVE N FROM (REAL) KEYBOARD
FOR count FROM 2 TO N STEP 2 DO
	SEND count TO DISPLAY
END FOR

☆ while loops

a while loop checks if the condition is true, and runs the code continously until it is not

• it will exit the loop when the condition is false
• loop is pre-tested pre-condition [make this sentence form / clearer]
• may or may not be executed [make this sentence form]

WHILE <condition> DO
	<statements>
END WHILE

pseudocode example:

SET i TO 0
WHILE i < 5 DO
	SEND i TO DISPLAY
	SET i TO i + 1
END WHILE

this displays:

0
1
2
3
4

☆ repeat… until loop