Whirlpool

Begin mainprogram
set cash to 100
repeat
Get payment
cash = payment + cash
until cash > 50
Print cash
End Program

this is a school task , and they said if the payment = '20' , what would the outout be. I am quit confused coz if you set cash to 100, the cash is > 50 already and doesnt need to enter the loop. and just prints 100

Metoo writes...

I am quit confused coz if you set cash to 100, the cash is > 50 already and doesnt need to enter the loop. and just prints 100

Begin mainprogram
set cash to 20

$ repeat
Get payment
cash = payment + cash
until cash > 50

$ Print cash
End Program

what would happen here?
Thats what they're asking

Some loops ALWAYS evaluate once. That is why there are several sorts of loops (Some loops may never loop). You might not want the loop to evaluate once if some conditions are met.

So you have to figure out (when you are writing a program), if you want the loop to always run at least once.

Your job is to workout what sort of loop this is. Maybe it is the wrong sort (or maybe it is not).

Metoo writes...

just prints 100

cash = 100
payment = 20

Since the exit condition (cash > 50) is evaluated after cash = payment + cash, then it will print "120"

The loop used in your pseudocode is a post-test loop meaning the loop is executed once and then the condition is evaluated. Therefore cash = 120.

just to elaborate on what others are saying...

Metoo writes...

repeat

Get payment

cash = payment + cash

until cash > 50

it is a bottom driven loop. which means that it will *always* execute at least once before checking a condition.

http://www.gailer-net.de/tutorials/java/Notes/chap44/ch44_3.html

notice how the "until" line is executed last.

if it was a top driven loop it would start

until cash > 50
yada
yada
yada
repeat

Repeat
Task
Until Condition

Will always run the task once before evaluating the condition.

While condition
Task
End While

Will only run the task if the condition is true. If the condition is false then nothing happens.

Don't get intimidated, just read it line by line like you are a dumb computer, doing exactly what it says.

set cash to 100 --- woo 100!
repeat — ok!
Get payment — woo, got 20!
cash = payment + cash --- yay now i have 120 in my cash!
until cash > 50 --- hrmmm cash is more than 50, so i dont repeat
Print cash --- "120"!
End Program --- yay!

AMD CPUs aren't as happy about things though, they tend to grumble a lot.

phx writes...

AMD CPUs aren't as happy about things though, they tend to grumble a lot.

That's not my CPU, that's my stomach.
Feed me! Feed me!

phx writes...

just read it line by line like you are acting dumb

who said i was acting? :P