@programminginc - страница 3165

Anonymous

void f(); int main() { int a, b; f(a, b); } void f() { do something; }

Anonymous

works

Mahdi

In my opinion its best usage is when a function doesn't return anything

Anonymous

but void f() { do something; } int main() { int a, b; f(a, b); } is a compile error

Anonymous

In my opinion its best usage is when a function doesn't return anything

What is the advantage or Use of void ? When we can do without void even for the function that doesn't return anything

Anonymous

"An empty list in a function declarator that is part of a definition of that function specifies that the function has no parameters" - From C18 standard So int main(){} and int main(void){} are essentially the same

Anonymous

void f(); int main() { int a, b; f(a, b); } void f() { do something; }

@K_P_Shetty this works when you don't write the void inside f(), which is dangerous

Mahdi

What is the advantage or Use of void ? When we can do without void even for the function that doesn't return anything

Functions must have return type. But when a function does not return anything we mark it void to tell nothing returns to the caller

Mahdi

Functions must have return type. But when a function does not return anything we mark it void to tell nothing returns to the caller

We can not leave the return nothing instead we say void

Anonymous

Functions must have return type. But when a function does not return anything we mark it void to tell nothing returns to the caller

So the advantage is execution speed will be better?

Anonymous

@K_P_Shetty this works when you don't write the void inside f(), which is dangerous

I am dumb, could you please elaborate what is dangerous in it ?

Mahdi

So the advantage is execution speed will be better?

It is not advantage. It is the rule.

Mahdi

You have to use void for function returning nothing

Anonymous

@K_P_Shetty this works when you don't write the void inside f(), which is dangerous

It is actually Undefined Behavior. When you say it works, I hope you meant to say that it compiles fine

Anonymous

We can not leave the return nothing instead we say void

Ok 👍

Mahdi

Ok 👍

👌✋

ʟᴏɴᴇᴡᴏʟꜰ

https://www.quora.com/What-is-the-use-of-void-in-c

Anonymous

https://www.quora.com/What-is-the-use-of-void-in-c

😅👍

Anonymous

It is actually Undefined Behavior. When you say it works, I hope you meant to say that it compiles fine

yeye

Anonymous

But here he is using int main(void) for every program with return 1 at the end...I am right now working for array programs

ʟᴏɴᴇᴡᴏʟꜰ

But here he is using int main(void) for every program with return 1 at the end...I am right now working for array programs

Because the function is returnable but has no parameters

Anonymous

Because the function is returnable but has no parameters

Ok thanks, if parameters exists in the programs then we should avoid void ?

Anonymous

I am dumb, could you please elaborate what is dangerous in it ?

https://en.wikipedia.org/wiki/Undefined_behavior there are entire languages designed to avoid undefined behaviour in all but specifically marked lines of code (Rust, Zig)

ʟᴏɴᴇᴡᴏʟꜰ

Yes

Anonymous

Ok thanks, if parameters exists in the programs then we should avoid void ?

You have it the other way round. In C, if a function takes no parameters and you are declaring it without a definition then you should use void in the paremeter list. If you are defining it, you can use either an empty parameter list or void in the parameter list. Both essentially mean the same.

ʟᴏɴᴇᴡᴏʟꜰ

You can leave the parameters region empty it will work even if you don't use void there

Anonymous

You can leave the parameters region empty it will work even if you don't use void there

Not if it is a function declaration in C where an empty parameter list is construed as an unknown number of arguments of unspecified types.

ʟᴏɴᴇᴡᴏʟꜰ

Okay

Anonymous

But here he is using int main(void) for every program with return 1 at the end...I am right now working for array programs

There is nothing wrong with it. Though the general practice is for programs that successfully complete to usually return 0 and a non zero return from main usually means an error condition. But if you don't use the return value in some other program, it doesn't matter what integer value you return from main.

Anonymous

Fine 😊 Thanks a ton for everyone, had many ideas on it 🙏🙏🙏

Anonymous

@ REX

Anshul

Can anyone suggest what is the best place to learn the core subjects for interview preparation?

Toluwap

Can anyone suggest what is the best place to learn the core subjects for interview preparation?

YouTube can be of great help

olli

Can anyone suggest what is the best place to learn the core subjects for interview preparation?

Cracking the coding interview is a great book for interview preparation

Anonymous

Can anyone suggest what is the best place to learn the core subjects for interview preparation?

I would also suggest to try out competitive programming.

Suyash

Cracking the coding interview is a great book for interview preparation

Yeah..! But Personality & Motivation/Confidence is also play big roll

Luiz

Thanks rose😅😊

Ajay

Thank you @MissRose_bot Read the pinned message

Anshul

Cracking the coding interview is a great book for interview preparation

Does that cover cse subjects like DBMS OS because I'm from electrical engineering

olli

Does that cover cse subjects like DBMS OS because I'm from electrical engineering

no, I would not consider DBMS to be a "core subject" for general interviewing. and neither is OS. it does cover basics of C++, Threads, Locks, Data structures and so on. (TOC)

Anshul

no, I would not consider DBMS to be a "core subject" for general interviewing. and neither is OS. it does cover basics of C++, Threads, Locks, Data structures and so on. (TOC)

Ok but I am covering data structures for some other course. Can you suggest me how to have a basic knowledge of DBMS OS computer network. Because they're asked in interview

バレンタインがいない柴（食用不可）

Time for late lunch

Anonymous

Ok but I am covering data structures for some other course. Can you suggest me how to have a basic knowledge of DBMS OS computer network. Because they're asked in interview

freecodecamp youtube

mito

freecodecamp youtube

ohh no.

Anonymous

pii means pair<int, int> vector<vector<pii>> par(N); WORKS: par = vector <vector<pii>>(n, vector<pii>(m, {0, 0})); DOESN'T WORK WHEN I PUT UNDER NESTED LOOPS WITH THIS: par[i][j].first = 0; par[i][j].second = 0; Tested with par[i][j]={0,0}; too

Anonymous

#include<iostream.h> #include<conio.h> void main() { long int n; cout<<"enter mob_no"; cin>>n; if(n!=11) { cout<<"you entered more than 10 digits"; } else { cout<<" your mobile no is:"<<n; } }

Anonymous

#include<iostream.h> #include<conio.h> void main() { long int n; cout<<"enter mob_no"; cin>>n; if(n!=11) { cout<<"you entered more than 10 digits"; } else { cout<<" your mobile no is:"<<n; } }

Guys i want to enter 10 digits no only more than 10 it would say your no is more than 10

kj

#include<iostream.h> #include<conio.h> void main() { long int n; cout<<"enter mob_no"; cin>>n; if(n!=11) { cout<<"you entered more than 10 digits"; } else { cout<<" your mobile no is:"<<n; } }

the thing is u r taking a 10 or 8 or 9 digit number for ex 8439849*** it will always be bigger than the number 10 u have to check the length not the value

Anonymous

pii means pair<int, int> vector<vector<pii>> par(N); WORKS: par = vector <vector<pii>>(n, vector<pii>(m, {0, 0})); DOESN'T WORK WHEN I PUT UNDER NESTED LOOPS WITH THIS: par[i][j].first = 0; par[i][j].second = 0; Tested with par[i][j]={0,0}; too

Can't help you much with the information you have given. But I think the problem is that you are trying to access elements that don't exist when indexing into the vectors. vector<vector<pii>> par(N) Here par is a vector of length N of empty vectors of pii. So when you use indexes i and j into this vector par, the index j refers to non existing elements.

Anonymous

the thing is u r taking a 10 or 8 or 9 digit number for ex 8439849*** it will always be bigger than the number 10 u have to check the length not the value

Shall i use strlen()?

Steven

#include<iostream.h> #include<conio.h> void main() { long int n; cout<<"enter mob_no"; cin>>n; if(n!=11) { cout<<"you entered more than 10 digits"; } else { cout<<" your mobile no is:"<<n; } }

if n>10000000…

kj

Shall i use strlen()?

one method is to take input in string and use the .length() function

kj

there are various ways of doing the same thing

Anonymous

👍

kj

if n>10000000…

this could also be done

Anonymous

this could also be done

It work5

kj

It work5

good..

Anonymous

Guys one more doubt!

Anonymous

How to use != operator?

Anonymous

In programing

DEV 7

Guys one more doubt!

means not equal to

DEV 7

In programing

for example i=5,j=6; if(i!=j){ cout<<" not equal"; }

Rocky

.

Hanz

Hey guys, I'm in need of someone who can be contacted on a small daily basis for C related understanding -- not problems, I can try to solve it by myself If anyone can help me with this, feel free to inform me via PM or just mention me here. I need serious person, not anonymous one. Thank you