Description

Conditionally executes a group of statements, depending on the value of an expression.

Syntax

if (condition)
     statement1
[else
     statement2]

Part	Description
condition	A Boolean expression. If condition is null or undefined, condition is treated as false.
statement1	The statement to be executed if condition is true. Can be a compound statement.
statement2	The statement to be executed if condition is false. Can be a compound statement.

Remarks

It is generally a good idea to enclose statement1 and statement2 in braces ('{}') for clarity and to avoid inadvertent errors. For the following example you may want the else to be used with the first if statement, but it is used with the second one.

if (x == 5)
  if (y == 6)
     z = 17;
else
  z = 20;

Changing the code to read:

if (x == 5)
  {
  if (y == 6)
     z = 17;
  }
else
  z = 20;

eliminates any ambiguities.

Later on, if you wanted to add a statement to statement1, and you didn't use the braces, you could accidentally create an error:

if (x == 5)
  z = 7;
  q = 42;
else
  z = 19;

In this case, there is a syntax error, as there is more than one statement between the if and else statements. Putting braces around the statements between the if and else is required.

© 1996 by Microsoft Corporation.