C#•2mo ago

scope of a for loop

what is the scope of i in for (int i = 0; i < Length; i++) { }? does it only exist within the for loop? if i want i to be used outside, i need this right?

i = x
for (int i = 0; i < Length; i++) { }

i = x
for (int i = 0; i < Length; i++) { }

this would break?

for (int i = 0; i < Length; i++) { }
x = i

for (int i = 0; i < Length; i++) { }
x = i

88 Replies

سَلْمَانْ حَيدَرْ•2mo ago

$tias

MODiX•2mo ago

https://images-ext-1.discordapp.net/external/CO2vsU2aXbRqYy1RdewOYnkBq1nGFBjdbjlNgjvG67A/https/media.discordapp.net/attachments/364492811489509376/964064233035816990/unknown.png?width=543&height=257

ElectricTortoiseOP•2mo ago

ok fair enough i want my code to look neat tho and ChatGPT did this

int i = 0;
for (; i < Length; i++)
{
  //Do stuff
}

int i = 0;
for (; i < Length; i++)
{
  //Do stuff
}

It can do that??? How does the for loop know what to use in front of the ;

سَلْمَانْ حَيدَرْ•2mo ago

lmao why are you doing that

ElectricTortoiseOP•2mo ago

i should show the full code hang on

int numberOfCaptures = 0;
for (; numberOfCaptures < moveList.Length; numberOfCaptures++)
{
    if ((moveList.Moves[numberOfCaptures] >> 12) != (int)MoveFlag.Capture)
        break;
}

int numberOfCaptures = 0;
for (; numberOfCaptures < moveList.Length; numberOfCaptures++)
{
    if ((moveList.Moves[numberOfCaptures] >> 12) != (int)MoveFlag.Capture)
        break;
}

سَلْمَانْ حَيدَرْ•2mo ago

dont do that just use the normal for loop syntax

ElectricTortoiseOP•2mo ago

right now, moveList is a bit longer than numberOfCaptures so i wanna count numberOfCaptures

int numberOfCaptures;
for (numberOfCaptures = 0; numberOfCaptures < moveList.Length; numberOfCaptures++)
{
  if ((moveList.Moves[numberOfCaptures] >> 12) != (int)MoveFlag.Capture) { break; }
}

int numberOfCaptures;
for (numberOfCaptures = 0; numberOfCaptures < moveList.Length; numberOfCaptures++)
{
  if ((moveList.Moves[numberOfCaptures] >> 12) != (int)MoveFlag.Capture) { break; }
}

so like that?

سَلْمَانْ حَيدَرْ•2mo ago

i dont get it why do you need to do this , you should use normal for loop syntax, if you need to keep track of a value e.g count then use an extra variable

ElectricTortoiseOP•2mo ago

i need numberOfCaptures to splice the array im working with so my plan is to count it first, then make another loop going up to numberOfCaptures only

Jimmacle•2mo ago

it doesn't "know" anything, all 3 expressions inside a for loop's parentheses are optional for (;;) is valid code

ElectricTortoiseOP•2mo ago

ooo

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

lmfaoooo true true the LLM sucks

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ElectricTortoiseOP•2mo ago

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ElectricTortoiseOP•2mo ago

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

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ElectricTortoiseOP•2mo ago

not really

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

lmfao

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

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ElectricTortoiseOP•2mo ago

i try my best to understand the code im doing

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

but sometimes it's hard to find good sources

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ElectricTortoiseOP•2mo ago

ChatGPT is surprisingly organised even though the code it spits out is broken half the time

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

yea that's what i use it for mostly

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

yea so i didnt copy paste the result i came here to ask what the result is doing

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

ummmm ok so... what's the scope of a for loop that was the question i came here with

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ElectricTortoiseOP•2mo ago

for (int i = 0; i < Length; i++) { }
x = i

for (int i = 0; i < Length; i++) { }
x = i

but i is declared within for()

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

so this wont work but then where is the i defined jimm said for(;;) is legal

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ElectricTortoiseOP•2mo ago

int i = 0;
for (; i < Length; i++)
{
  //Do stuff
}

int i = 0;
for (; i < Length; i++)
{
  //Do stuff
}

and this was GPT's code

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

ooo i havent

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

mmmm ok

SG97•2mo ago

and stop using gipity

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ElectricTortoiseOP•2mo ago

ngl i kinda overlooked the for loop's docs bcs i use it so often in the for (int i = 0; i < Length; i++) so like i kinda assumed that was it never really thought about what goes on behind the scenes tho

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ElectricTortoiseOP•2mo ago

i only use it as a glorified search engine when google wont tell me what i want

SG97•2mo ago

aight

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

aha so it's a glorified while loop

ElectricTortoiseOP•2mo ago

ooooooooo ok

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ElectricTortoiseOP•2mo ago

wowzers ok

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ElectricTortoiseOP•2mo ago

ooo ok also after reading just a small part of the docs i think i understand what ChatGPT did

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

It did not include the initializer, so C# defaulted to using whatever value the variable had beforehand

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

is that correct

Unknown User•2mo ago

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ElectricTortoiseOP•2mo ago

makes sense makes sense just had a stupid idea: can you use a for loop as a while loop

FusedQyou•2mo ago

tl;dr This is fine, a for loop is not required to define a variable to loop, but it does require the semicolons to be defined. As jimmacle mentioned this makes for(;;) valid but it would be the same as an infinite while loop. Depends on use case This is wrong, no such thing as a "normal" loop and what they wrote is very valid Finally, scope is anything in {} brackets. You should understand that scope is not a strict thing and {} is valid anywhere in the code, not just if-statements or things like that. You can nest {} infinitely and it would technically make a new scope each time. It's just most commonly used in for-loops/if-statements/while-statements because they are tied to execute a single line otherwise and this way you execute a whole scope. I personally use scopes if I have common names for variables and I define them multiple times, but they vary per context. It's nice being able to wrap them in {} so the scope gets rid of the name so I can just redefine them later.

ElectricTortoiseOP•2mo ago

oh so i can literally just place {} anywhere and it would define a scope?

FusedQyou•2mo ago

Yes

void Main()
{
  int foo = 0;

  {
    int bar = 0;

    // Legal, defined in parent scope
    foo = 5;
  }

  // Not legal, defined in disposed scope
  bar = 5;
}

void Main()
{
  int foo = 0;

  {
    int bar = 0;

    // Legal, defined in parent scope
    foo = 5;
  }

  // Not legal, defined in disposed scope
  bar = 5;
}

I guess "disposed" is not the right word here but you get what I mean

FusedQyou•2mo ago

Ignore the other errors, but notice it has no idea what bar is

FusedQyou•2mo ago

This is valid code

FusedQyou•2mo ago

Again ignore the errors, this is just the analyzer complaining the method and variable are not actually used

ElectricTortoiseOP•2mo ago

ooo ok also whyare your "not actually used errors" red instead of green

FusedQyou•2mo ago

My project explicitly marks warnings and/or suggestions as errors to improve the code written

ElectricTortoiseOP•2mo ago

mine does that too but green instead of red

FusedQyou•2mo ago

If you want you can change it to instead be errors if you want.

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Jimmacle•5w ago

green is a suggestion, technically

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Jimmacle•5w ago

warnings are yellow, though suggestions are green and don't really mean anything, they're just options for something you can do

Unknown User•5w ago

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Jimmacle•5w ago

what did you do to your IDE :kekw:

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Jimmacle•5w ago

weird

Unknown User•5w ago

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Jimmacle•5w ago

what underline color are suggestions then

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ElectricTortoiseOP•5w ago

That's pretty nutty Ah yea this is for code that isn't actually used right

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scope of a for loop

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