What is the output, and explain how you got the answer.

Question

int × [6];
for ( int i=0; i <6; i++)
{
x [i] = i+3;
if(i>=4)
x [i-1]= ×[i]+4
}

//Display content of the array.
for (i=0; i <6; i++)
cout <<x [i] << " ";

Answer 1

Step by step:

x[0] = 0 + 3 = 3. i = 0
x[1] = 1 + 3 = 4. i = 1
x[2] = 5. i = 2
x[3] = 6. i = 3
x[4] = 7. i = 4

i is now >= 4!
x[4-1] = x[3] = x[4] + 4 = 7 + 4 = 11
So x[3] is now 11.

x[5] = 8. i = 5

i is >= 4!
x[5-1] = x[4] = x[5] + 4 = 8 + 4 = 12
So x[4] is now 12.

i = 6, 6 < 6. False. Therefore the loop is finished.

~~~~Errors~~~~
Compilation ERROR variable i not declared.
Fix: (int i = 0.....etc
Compilation ERROR, you used different letters for your 'x'.
Compilation ERROR missing semi-colon.
Fix: x [i-1] = x[i] + 4;
~~~~~~~~~~~~

Assuming no mistakes were made:

Output:
3 4 5 11 12 8

The real output is error though 😛.

Answer 2

Its from the line:
x[i] = i + 3.
At the moment i = 5.

Answer 3

Careful, x is the array. I think you mean i. 😜

i went up to 5. I've just posted everything in order of execution.

So after x[4] was the if statement/next operation. Then it went to x[5].

i doesn't go up to 6 though, that's when the loop stops.

I've editted the original post by adding an extra space after x[5]. Hopefully it's easier to see now.

Answer 4

Ahh, of course! Thank you!

Answer 5

Ohhhh, okay! Makes sense! Thanks a lot :D

Answer 6

How did you get x [5]=8?? Unsure where that came from.

Answer 7

Also, why does x only go up to 4, and not 5? Thought the array size was six.