C# Challenge question... 🤔

Question

https://www.sololearn.com/post/1335223/?ref=app

Which of the following are valid, given:
int x = 0; ?
Select all that apply.

a. 5 + x = x;
b. x = x + 5;
c. x += 5;
d. x == x + 5;
Sololearn's correct answers are b and c.

Question: why is d not a correct answer?... 🤔

Answer 1

== is equality operator
in js we also have === to check type and value

so, if you wanna add some value to a variable you gotta do it these ways:

x = x + 1;
or
x += 1;
not
x == x + 1;

int x = 0;

Console.WriteLine(x =+ 1); => 1
Console.WriteLine(x = x + 1); => 2
Console.WriteLine(x == x + 1); => false

So, you are right somehow

but this....

int x = 0;

x == x + 1;
Console.Write(x);

will give an error

https://code.sololearn.com/c52vFjE7xeZH

Answer 2

Ahmed Afgooye 🇸🇴 🇸🇴 & Sayed
Thanks.
I get the explanation but the question didn't state that we are comparing or just assigning values.
Console.WriteLine(x == x + 5); is valid right?

Answer 3

JOY
Thanks once more. You seem to be the only one that gets my point. 😅

Answer 4

Your logic is right!
As for validity ,I think it is right.
The results are not the same.

Answer 5

JOY
I get that.
Maybe I'm thinking too much. The question is about validity.
The 2 operands are not equal and hence, the programs outputs false.

Answer 6

you need only "=" you're assigning not comparing

Answer 7

👑 Tchybooxuur!
(x == x + 5) is valid when we use it in condition like

if (x==5)
// do it

But when we write it directly like
x == 5 //it will throw an error.

Answer 8

Most welcome bro. TBH I was biased in the beginning too as am too much used to with the question. But I realised your logic soon

Answer 9

Brahmeswara Rao:
Thanks uncle Rao 👍🏼

Answer 10

Danny-Durand NZIGAMASABO

valid (adj): /ˈvalɪd/
1) (of an argument or point) having a sound basis in logic or fact; reasonable or cogent.

"a valid criticism"

2) based on truth or reason. Able to be accepted.

int x = 0;
x == x + 5; is a valid construct.

The question only asks whether it's valid. It doesn't say anything else.

5 + x = x (not valid in C#)

Answer 11

"==" is equality operator, meaning "does the value at the value at the right equal to the value at the left".

"=" is an assignment operator, meaning "the right value is assigned to the left one".

Answer 12

beginning too as am too much used to with the question. But I realised your logic soon

Answer 13

ابو كيان نعمان
👍🏼 🌼