Please help with these 3 question that I can't for the life of me figure out. With explanations obviously.


1) Karel robot is facing north.
------------------------------------
while ( !karel.facingEast() )
{
karel.turnLeft();
}
karel.turnLeft();
-----------------------------------
Where will Karel robot be facing after performing the above task?
a) North
b ) South
c) East
d) West
e) Infinite loop

2) Considering there are no walls in the grid and a beeper in every crossing, where will Karel robot be after completing this task, considering he is currently facing north at (10,10).
-----------------------------------
void method1(){
iterate 4 times{
iterate 6 times{
move();
pickBeeper();
}
turnLeft();
}
}
----------------------------------
a) (16,10)
b ) (10,10)
c) (4,10)
d) (10,16)
e) None of the above

3) Considering there are no walls in the grid and a beeper in every crossing, and the robot is facing north at (10,10), how many beepers will he have in his beeper bag after completing each method seperately?
----------------------------------
void method1(){
iterate 4 times{
iterate 6 times{
move();
pickBeeper();
}
turnLeft();
}
}

void method2(){
iterate 6 times{
iterate 4 times
move();
turnLeft();
}
pickBeeper();
}

void method3(){
iterate 24 times{
move();
pickBeeper();
turnLeft();
}
}\
-----------------------------

This is my interpretation of what happens for #1.



Karel is facing north.
While loop condition met, Karel turns left.

Karel is now facing West.
The while loop condition is checked again.
Condition still met, Karel turns left.

Karel is now facing South
The while loop condition is checked again.
Condition still met, Karel turns left.

Karel is now facing East.
The while loop condition is checked again.
WHILE LOOP ENDS

Karel turns left.
Karel is facing North.

Excuse my ignorance but why did you make him turn left 4 times?

How this while loop works:
This while loop will run the {code} in the brackets until Karel is facing East. (That's what the first line reads)

So when Karel is NOT facing East run the {code}. Once the code inside the brackets is finished running re-evaluate if he is facing east.(loops back to the start of the while loop - line 1)
It will continue to loop and execute the {code} until Karel faces East.

Why I made him turn 4 times
I made him turn 3 times as a result of the while condition being met.
The last turn is because once the while loop finished there is another karel.turnLeft(); - which happens after the while loop ends.


I hope this helped. Heading to bed.

If this still doesn't make sense google a 'while loop tutorial' - might make more sense.

Thanks buddy!

I concur.

As for the other two I'm not sure what exactly it means iterate 4 times.

This post was edited by ROM on Oct 30 2015 09:07am

It looks like the code is pseudo-code, not an actual programming language. As such, "iterate 4 times { .... }" is equal to " for(x=0; x<4; x++) { .... } "

Basically it means, "run this loop X times"