Microsoft Visual C++/cli step by Step

 

CHAPTER 5

 

Decision and loop statements 

 75

Quick reference

To

Do this

Perform a one-way test.

Use the if keyword followed by a test enclosed in paren-

theses. You must enclose the if body in braces if it con-

tains more than one statement. For example:

if (n < 0)  

{ 

    Console::Write("The number "); 

    Console::Write(n); 

    Console::WriteLine(" is negative"); 

}

Perform a two-way test.

Use an if-else construct. For example:

if (n < 0)  

{  

    Console::Write("Negative"); 

} 

else 

{ 

    Console::Write("Not negative"); 

}

Perform a multiway test.

Use an if-else-if construct. For example:

if (n < 0)  

{ 

    Console::Write("Negative"); 

} 

else if (n == 0) 

{ 

    Console::Write("Zero"); 

}  

else 

{ 

    Console::Write("Positive"); 

}

Test a single expression against a finite set of constant 

values.

Use the switch keyword followed by an integral expres-

sion enclosed in parentheses. Define case branches for 

each value you want to test against, and define a default 

branch for all other values. Use the break statement to 

close a branch. For example:

int dayNumber; // 0=Sun, 1=Mon, etc.  

…  

switch (dayNumber)  

{  

case 0:  

case 6:  

    Console::Write("Weekend");  

    break;  

default:  

    Console::Write("Weekday");  

    break;  

}

Perform iteration by using the while loop.

Use the while keyword followed by a test enclosed in 

parentheses. For example:

int n = 10;  

while (n >= 0)  

{ 

    Console::WriteLine(n);  

    n--;  

}

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