use... in switch()

Question

#include <iostream>
using namespace std;

int main()
{
int a=0;
cin>>a;
switch(a)
{
case 10...20:
cout<<"to low!";
break;
case 20...30:
cout<<"not bad!";
break;
default:
cout<<"not in cases!";

}
return 0;
}
there is a bug !
[Error] too many decimal points in number
what is it meaning????

Answer 1

10...20 I assume is a range. Unlike some other languages, c++ does not use these. You're going to have to use if-else-if sentences.

if (a >= 10 && a < 20) {
cout << "Too low!\n";
} else if (a >= 20 && a <= 30) {
cout << "Not bad!\n";
} else {
cout << "Not in cases!\n";
}

Answer 2

@Nafiseh, the last time I see three dots used to define a range was years ago, in a Delphi (Pascal) snippet, so I think it's used in such language.

This is not supported in C++, you may want to try the sample from @Sreejith or @Zeke instead. I have also been looking for this matter and I think I found the answer here.

Thanks everyone.

Answer 3

l just want to know how and where can I use these three dots!

Answer 4

I don't think they are used in c++

Answer 5

case 10...20.
//too many decimal points.its wrong way declaring case

it should be
case(a>=10 && a<=20)

Answer 6

so what case we can use ... ???

Answer 7

case "string" :
//for declaring string

case 'char':
//for declaring character

see the difference???

Answer 8

I mean when can l use these 3 dots???

Answer 9

you can't use them in switch statement.

Answer 10

where we can use so????

Answer 11

why do you want to use them

Answer 12

i think 3 dots are used in python or ruby
but first tell me why do u want to use them

Answer 13

this is not like chatting bro... here 3 dots are considered as 3 decimal points which is not possible