compare an input to see if it's contained within a paramter list

[Maxd out]

Hi all

As a newbie to C++ just wondering if you can compare a user input e.g. the
integer 2 to see if that integer is contained within a parameter list. If so
how can it be done and can it be done by referencing?

Tks

 

[Mike Wahler]

Hi all

As a newbie to C++ just wondering if you can compare a user input e.g. the
integer 2 to see if that integer is contained within a parameter list. If so
how can it be done and can it be done by referencing?

#include <iostream>

bool contained(int& param1, int& param2, int& param3)
{
int input(0);
return (std::cin >> input) && (input == param1 ||
input == param2 ||
input == param3);
}

int main()
{
std::cout << "User input is"
<< contained(1, 2, 3) ? " " : " not "
<< "contained in parameter list\n";

return 0;
}

Did you mean something else?

-Mike

 

[Kevin Goodsell]

Hi all

As a newbie to C++ just wondering if you can compare a user input e.g. the
integer 2 to see if that integer is contained within a parameter list.

Uh... I guess you could do this:

void func(int a, int b, int c, int d)
{
std::cout << "enter an integer: ";
int i;
std::cin >> i;

if (i == a || i == b || i == c || i == d)
{
std::cout << "That number is in the parameter list" << std::endl;
}
else
{
std::cout << "That number is not in the parameter list" << std::endl;
}
}

But somehow I don't think that's what you mean. Are you sure "Parameter
list" is the term you wanted to use?

If so
how can it be done and can it be done by referencing?

What is "referencing"?

Your question is very unclear.

-Kevin

 

[Chris \( Val \)]

|
| | > Hi all
| >
| > As a newbie to C++ just wondering if you can compare a user input e.g. the
| > integer 2 to see if that integer is contained within a parameter list. If
| so
| > how can it be done and can it be done by referencing?
|
|
| #include <iostream>
|
| bool contained(int& param1, int& param2, int& param3)
| {
| int input(0);
| return (std::cin >> input) && (input == param1 ||
| input == param2 ||
| input == param3);
| }
|
| int main()
| {
| std::cout << "User input is"
| << contained(1, 2, 3) ? " " : " not "
| << "contained in parameter list\n";

std::cout << "User input is "
<< contained( 1, 2, 3 ) ? std::cout << " " :
std::cout << " not contained in parameter list\n";


Hello Mike, you left a couple of important bits out .

Btw, why not pass by const reference, or by value ?
It saves the warnings about temporaries.

Cheers.
Chris Val

 

[Kevin Goodsell]

|
|
| #include <iostream>
|
| bool contained(int& param1, int& param2, int& param3)
| {
| int input(0);
| return (std::cin >> input) && (input == param1 ||
| input == param2 ||
| input == param3);
| }
|
| int main()
| {
| std::cout << "User input is"
| << contained(1, 2, 3) ? " " : " not "
| << "contained in parameter list\n";

std::cout << "User input is "
<< contained( 1, 2, 3 ) ? std::cout << " " :
std::cout << " not contained in parameter list\n";

I don't believe there is an operator<<(ostream, ostream) available, so
your code will not compile. Even if it did it wouldn't give the right
output. The original code was fine.

Hello Mike, you left a couple of important bits out .

Btw, why not pass by const reference, or by value ?
It saves the warnings about temporaries.

You are right on this point. But I think the warnings should be errors.

-Kevin