For Javascript, I'm also trying to solve this by try catch but it is very very basic concept. You do not need to use that, it solved by using isNAN() method and print the output accordingly.

it can be soved by simply this one below line :

console.log( isNaN(S) ? "Bad String" : S);

Python 3

Just clear everythig else previously given i.e. all the import statements and if name==..

s = input()
try:
    print(int(s))
except ValueError:
    print("Bad String")

I don't konw what is the problem of this

try:
        print(int(S))
except ValueError:
        print("Bad String")

result: Error reading result file.You should use exception handling concepts.

I

Do not use any println in comments for Java, otherwise test case fail due to stupid judging system.

C++

int main()
{
    string S;
    getline(cin, S);
    int t;
    try{
       t= stoi(S.c_str());
       cout << t;
    }
    catch (const exception& e){
    //  cout << e.what() << endl;
        cout<<"Bad String";
    }
    return 0;
}