Formatting if else Statements

Keep in mind that the two alternatives in an if else statement must be single statements. If you need more than one statement, you must use braces to collect them into a single block statement. Unlike some languages, such as BASIC and FORTRAN, C++ does not automatically consider everything between if and else a block, so you have to use braces to make the statements a block. The following code, for example, produces a compiler error:

if (ch == 'Z')
    zorro++;       // if ends here
    cout << "Another Zorro candidate ";
else               // wrong
    dull++;
    cout << "Not a Zorro candidate ";

The compiler sees it as a simple if statement that ends with the zorro++; statement.

Then there is a cout statement. So far, so good. But then there is what the compiler perceives as an unattached else, and that is flagged as a syntax error.

You add braces to group statements into a single statement block:

if (ch == 'Z')
{                       // if true block
    zorro++;
    cout << "Another Zorro candidate ";
}
else
{                      // if false block
    dull++;
    cout << "Not a Zorro candidate ";
}

Because C++ is a free-form language, you can arrange the braces as you like, as long as they enclose the statements. The preceding code shows one popular format. Here’s another:

if (ch == 'Z') {
    zorro++;
    cout << "Another Zorro candidate ";
    }
else {
    dull++;
    cout << "Not a Zorro candidate ";
    }

The first form emphasizes the block structure for the statements, whereas the second form more closely ties the blocks to the keywords if and else. Either style is clear and consistent and should serve you well; however, you may encounter an instructor or employer with strong and specific views on the matter.