C++ Syntax: if (args)
Description
The if statement has the form:-
if ( expression ) statement
If the expression evaluates to true (not zero) the
following statement, which is normally a
compound statement
is executed. An optional else statement may follow immediately
(no intervening statements), for example:-
<![CDATA[
if ( a > b ) print " a > b\n";
else print "a <= b\n";
]]>
Usage Notes
Alternatives to if (args)
The
switch
statement is a good way to perform a multi-way
branch on a single value.
Multi-way ifs
There is no elseif statement. To make a multi-way branch
use a set of nested ifs, for example:-
<![CDATA[
if ( a > b ) print "a > b\n";
else if (a == b ) print "a == b\n";
else print "a < b\n";
]]>
Note in the above example that the else statement must belong to the
second if (the first if has an intervening statement). To be able
to match an else to an outer if requires the use of a compound statement e.g.:-
<![CDATA[
if ( a >= b ) {
if (a == b ) print "a == b\n";
else print "a > b\n";
}
else print "a < b\n";
]]>
Now the second if is hidden inside the compound statement and the second else
is the next statement after the first if. Also note how important it is
to align statements to improve readability!
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Nick West