The discussion revolves around understanding a Scratch programming code that initializes a variable 'a' to 5 and utilizes a "Repeat 10" block to modify 'a'. Participants clarify that the "change a by 1" instruction increments 'a' by 1 during each iteration of the loop, leading to a final value of 15 after 10 repetitions. The confusion arises from the distinction between "set" and "change by," with the former replacing the variable's value and the latter modifying it. Ultimately, the correct interpretation of the code confirms that 'a' increases from 5 to 15.
PREREQUISITESBeginner Scratch programmers, educators teaching programming basics, and anyone looking to understand variable manipulation within loop structures in Scratch.
Ok so if i set a=1. Then a <3 so a*2 = 1*2 = 2. If i repeat this process 10 times , what do i have to do with the a value each time. Add them up ? 2 *10= 20 which is option c) which is wrong. The correct answer is e) 15.Office_Shredder said:
There is no instructionTesla In Person said:
set a to 1, the instruction inside the loop is change a by 1. What is the value of a the first time it reaches this instruction?I thought "change a by 1" meant replace the value of 5 by 1.pbuk said:
You are not the first person to have been caught out by that, it's a confusing "feature" of Scratch.Tesla In Person said:
Yes.Tesla In Person said:
So we add 1 ? It becomes 6 and 6 is not smaller then 3 so we go back and keep adding 1 ? Repeating this 10 times gives a=15 which is correct.pbuk said:
No, as already mentioned. There's a difference between "set" and "change by". "Set" replaces the old value of the variable by some new value. "Change by" adds or subtracts some value to a variable. In the program "change a by 1" adds 1 each time in the loop. If it had said "change a by -2" it would have subtracted 2 each time in the loop.Tesla In Person said:
In the program, a's value is always >= 5, so the if condition is never executed. Essentially what the code does is to increase a (which starts off at 5) by 1 ten times, which results in a's final value being 15.Tesla In Person said: