4.2. if ... else
A second form of if statement exists which
allows you to also specify a block of code to execute if the test
expression is false. This is known as an if
... else statement and is formed by placing the reserved
word else and another block of code after the
usual if statment. You program will execute one of
the two blocks of code based on the test condition after the
if. Here's what it looks like:
Example 4-2. cows2.c
int
main()
{
int cows = 0;
if (cows > 1)
{
printf("We have cows\n");
printf("%d cows to be precise\n", cows);
}
else
{
if (cows == 0)
printf("We have no cows at all\n");
else
printf("We have only one cow\n");
}
if (cows > 10)
printf("Maybe too many cows.\n");
return 0;
}
You should be able to guess the output by now:
ciaran@pooh:~/book$ ./cows2
We have no cows at all
ciaran@pooh:~/book$
In the last example there was an
if .. else
statement inside another
if .. else statement. This
is perfectly legal in C and is quite common. There is another form of
branching you can use but it's a little more complex so we'll leave it
to to end of the chapter.
