C#•2y ago

✅ Hello, could you help me understand `&`, `&&`, `|`, `||` in C# with this code example:

int a = 4, b = 3, c = 2, d = 1;

if (a / b > 1 & c - d < 1 | a % 2 == 0)
    label1.Text = "everything's cool";
else
    label1.Text = "everything's bad";

int a = 4, b = 3, c = 2, d = 1;

if (a / b > 1 & c - d < 1 | a % 2 == 0)
    label1.Text = "everything's cool";
else
    label1.Text = "everything's bad";

Why does the

if

if

condition execute when

a/b>1

a/b>1

is

false

false

?

The ampersand

upon encountering the first

false

false

, immediately triggers

else

else

, and evaluates the rest of the expression in the background (right??). Its further calculation of other expressions after the

should not change the outcome (?), as it is not the OR operator

. Why do we then end up with 'everything's cool'?"

mtreit

M

mtreit•3/3/24, 12:19 AM

is not short-circuiting.

mtreit

M

mtreit•3/3/24, 12:19 AM

&&

&&

is

mtreit

M

mtreit•3/3/24, 12:22 AM

I'm not sure what you are asking actually, what do you mean by "evaluate the rest of the expression in the background" ?

mtreit

Mmtreit I'm not sure what you are asking actually, what do you mean by "evaluate the res...

flask

F

flaskOP•3/3/24, 12:24 AM

According to the information I have,

is an ampersand "and", returns false the first time False is triggered, but also counts the remaining expression in memory (not sure what are the use cases for it, maybe I'm wrong about it in the first place).

The double ampersand && does not read the rest of the expression the first time False (so a/b>1 gives False, the rest doesn't matter since it's already

else

else

), thus working faster.

mtreit

M

mtreit•3/3/24, 12:25 AM

You normally do not want to use non-short-circuiting operators for logical operations.

mtreit

M

mtreit•3/3/24, 12:25 AM

returns false the first time False is triggered, but also counts the remaining expression in memory

Whatever this is trying to say is not right.

mtreit

M

mtreit•3/3/24, 12:26 AM

The entire expression gets evaluated if you use

and

before producing a final result that is either

true

true

or

false

false

mtreit

M

mtreit•3/3/24, 12:27 AM

You also need to be careful to parenthesize your conditions to ensure it's doing what you think.

mtreit

M

mtreit•3/3/24, 12:29 AM

false & true | true

false & true | true

evaluates to true

false & (true | true)

false & (true | true)

evaluates to false

oke

O

oke•3/3/24, 12:29 AM

and

are called bitwise operators. They are used for manipulating binary numbers.

&&

&&

and

||

||

are boolean operators.

mtreit

M

mtreit•3/3/24, 12:29 AM

Well, they can also be used as logical operators.

mtreit

M

mtreit•3/3/24, 12:30 AM

As is the case here.

mtreit

M

mtreit•3/3/24, 12:30 AM

But yes normally you never use these except for bitwise operations.

mtreit

Mmtreit Well, they can also be used as logical operators.

oke

O

oke•3/3/24, 12:30 AM

for simplicity's sake, i narrowed it down

oke

O

oke•3/3/24, 12:30 AM

probably stole your thunder a little bit by saying it right after your novel

oke

Ooke probably stole your thunder a little bit by saying it right after your novel 😬

mtreit

M

mtreit•3/3/24, 12:31 AM

Nah it's fine

flask

Fflask ```csharp int a = 4, b = 3, c = 2, d = 1; if (a / b > 1 & c - d < 1 | a % 2 == ...

oke

O

oke•3/3/24, 12:32 AM

read this for more on binary operators: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators
read this for boolean operators: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/boolean-logical-operators

Bitwise and shift operators - perform boolean (AND, NOT, OR, XOR) a...

Learn about C# operators that perform bitwise logical (AND -

, NOT -

, OR -

, XOR -

) or shift operations(

<<

<<

, and

>>

>>

) with operands of integral types.

Boolean logical operators - the boolean and, or, not, and xor opera...

C# logical operators perform logical negation (

), conjunction (AND -

,

&&

&&

), and inclusive and exclusive disjunction (OR -

,

||

||

,

) operations with Boolean operands.

mtreit

M

mtreit•3/3/24, 12:33 AM

So

false & true | true

false & true | true

evaluates to true whereas

false && true | true

false && true | true

and

false && true || true

false && true || true

both evaluate to false

oke

O

oke•3/3/24, 12:33 AM

this whole thing is just a cluster fuck of c#

Moods

M

Moods•3/3/24, 12:34 AM

Please use your brackets though...to avoid ambiguities

flask

F

flaskOP•3/3/24, 12:35 AM

Thank you so much for your help

Denis

D

Denis•3/3/24, 9:35 AM

$close

Denis

MODiX

M

MODiX•3/3/24, 9:35 AM

Use the /close command to mark a forum thread as answered

✅ **Hello, could you help me understand `&`, `&&`, `|`, `||` in C# with this code example:** - C#