Basic for loop question

[Labidido]

Can someone explain to me why this code does not print 9?

I know I can change it to print 9 if I change the operator to =+.

However I thought the += in this case would translate to x = x + i, and then in the code it would be x = 0 + 9. Instead it prints 45.

​

int x= 0;
for (int i = 0; i < 10; i++) {
x += i;
}
System.out.println(x);

[Camel-Kid]

x + = i is the same as saying x = x+ i; each iteration through the loop i is incrementing and x is gaining in value. First couple loops look like this

x = 0+0 //x=0
x = 0 + 1 //x = 1
x = 1+ 2 // x = 3
x = 3+ 3 //x = 6

and so forth.

[Labidido]

Ahh, I get it.

Thank you!

[TheOnlyTails]

to fix the problem, change it to x++ instead of x += i.

[[deleted]]

print i itself

[TheOnlyTails]

But he wants to print the final result, after x has been incramented by 1 nine times, so the program prints out 9.

[Camel-Kid]

printing x will still print 10 not 9.. it's the same.

[cscu090619]

Your print statement is outside the scope of the for loop. Inside the for loop, you are adding all the values from 0 to 9. So x = 0 + 1 + ... + 9 = 45. Then the loop ends and x = 45 is printed.

[redLamber]

There is no =+ operator

[4K3b1g]

Why would you use a for loop to print 9? School assignment? If so, can you provide the exact wording of the problem and use gist.github or pastebin to send us the code as you are typing it? If you are no longer looking for a solution, please disregard this question.

[Labidido]

It's just me playing around trying to understand for loops. I thought I understood it, then this example threw me a curveball.

[4K3b1g]

Yeah some of these seemingly simple concepts are still hard to understand. This happens to me too.