While loop that displays no negative numbers

[Greatness]

How would i write a while loop that displays no negative numbers???

[Savage]

How would i write a while loop that displays no negative numbers???

It's quite simple.All that u need is simple if-else statment inside the loop if exppresion is TRUE don't print anything else print that number.


Savage

[Greatness]

ok so like this......



int n;
while (n = 0)
if (n>0)
cin >> n;
else (n < 0)
cout << " Please enter another number";


???? lol

[Ganon11]

ok so like this......

int n;
while (n = 0)
if (n>0)
cin >> n;
else (n < 0)
cout << " Please enter another number";

???? lol

Not quite...

Let's look at what your code is doing.

int n;
while (n = 0)
   if (n>0)
      cin >> n;
   else (n < 0)
      cout << " Please enter another number";

First, you declare an integer variable, n. Cool. Then you have a while loop, with a condition setting n to 0? Maybe you meant n == 0 which would loop while x is 0, but even then your loop will fail because you haven't given a value to n.

Now, inside the loop, you test if n is greater than 0. This would be great if n had a value...but you only cin >> a value if it's greater than 0. Huh? That doesn't make sense! How can you test its value before you get it?

Now, your else statement is incorrectly written. You cannot have else (condition) - you can only say else, or else if (condition). Also, the condition is not necessary - if a number is not greater than 0, then it must be less than 0 (or must it...what if n = 0? Consider this possibility).

[Savage]

ok so like this......



int n;
while (n = 0)
if (n>0)
cin >> n;
else (n < 0)
cout << " Please enter another number";


???? lol

I do see what u want to do but this is all wrong.Let us go line by line and fix this:

1.while(n=0)

I do see lots of errors here.If i get the program right it's supposed to be a control of input.

a.Couple of errors are here: while(n=0)

solution:instead of using number to identify when loop will break i would rather use identifer,in this case let it be i.Secound error u cant use a single = when testing expression,u must use ==.So here is fisrt part of it:

int i=0;
while(!i)//this is nearly same as while(i==0).

I see more errors in loop construction part:(e.g)

It should be this:

while(!i)
{
//loop body
}

When u have done all this 'repairment' post so that we can move forward.

Savage

[Greatness]

hmm ok so let me try this

int n;
cout << "Enter a Number"<<endl;
cin>> n;
while (n)
if (n>0)
elseif

[Greatness]

sorry posted that before i saw the last post

[Savage]

hmm ok so let me try this

int n;
cout << "Enter a Number"<<endl;
cin>> n;
while (n)
if (n>0)
elseif

It's not elseif it's else if(ur expression) and u are missing those{ } compund statments in ur loop

Savage

[Greatness]

ok i understand the first part please continue

[Savage]

ok i understand the first part please continue

Well as we can see it's already continued.Do u have any Q on those new posts?


Savage

[nirJianWu]

How would i write a while loop that displays no negative numbers???

I don't understand your requirement very much...

do you wanna display all the non negative numbers or you just want to display the non negative numbers you received.

if you wanna display all by using a while loop, just do it as follows..

int n = 0;
while(1)
std::cout<<n++<<std::endl;

but if you wanna display the non negative numbers you received, using a if-else statement is good idea.

[Greatness]

nah i'm still working on this one lol

so from what you have taught me today:


int i = 0;

cout<< "Please enter a number" << endl;
cin >> i;

while(i == 0)
{
if(i>0)
esle
}

[Greatness]

For this part of the program i want to create a while loop that will not display negative numbers.

[Savage]

No,no u still have number n defined, i is just identifer.

int n,i;

//loop and it's expression

//loop body

if(n>0) i=1;
else i=0;

} //loop compound statement.

Note:this task can be done much more easier if u use do-while.Do u must use while?

Savage

[Greatness]

We can you use do-while also...
Can you show me that way also???

[Savage]

We can you use do-while also...
Can you show me that way also???

Offcourse,it would be like:

int n;
 
do{
       //cin number
 
 
}while(n<0);//No need for those if-else statments at all

Savage

[Greatness]

whenever i try to use your code i get a runtime error saying that n has not been defined

[Savage]

whenever i try to use your code i get a runtime error saying that n has not been defined

And how did u exactly implemented my code?

PS:Post just do-while loop or while which u have used.

Savage

[Greatness]

well when i put the while in it say i, n have not been defined
but with the dowhile it just says n have not been defined

[nirJianWu]

int i = 0;

cout<< "Please enter a number" << endl;
cin >> i;

while(i == 0)
{
if(i>0)
esle
}

ur, it will print nothing...

in your code, the code inside while loop will be executed only when i ==0 .

[JosAH]

A while loop that doesn't display negative numbers:

for(;;) cout << 42;

kind regards,

Jos ;-)

[Savage]

well when i put the while in it say i, n have not been defined
but with the dowhile it just says n have not been defined

But in my code n is defined:

int n;

Post that part here.

Savage

[Savage]

A while loop that doesn't display negative numbers:

for(;;) cout << 42;

kind regards,

Jos ;-)

Yes offcourse.
How can i forget this.This is briliant.

He,he.

Good one Jos ;-)

How about this:

forever(;;) cout <<42;

Savage

[Banfa]

A while loop that doesn't display negative numbers:

for(;;) cout << 42;

Strictly speaking that is a for loop not a while loop, when I saw this post I had

while(1)
    ;
 

in mind. The point these posts Greatness is that your original question (specification) is so loose (poorly specified) that many many constructs will fit what you have said although most of them are unlikely to do anything close to what you want.

When you post your next question please try to be a little more precise.