06-06-2014, 07:49 AM
How to create a proper if/elseif construction
The Perl if/else syntax
The Perl if/else syntax is standard, I don't have any problems here:
The Perl "else if" syntax (elsif)
In Perl the "else if" syntax actually uses the elsif keyword. Here's some example code showing this syntax:
Perl's numeric and string comparison operators
While I'm in the neighborhood of Perl and tests (comparisons), here's a list of Perl's numeric and string comparison/equality operators:
Not knowing the Perl has different operators for numeric tests and string tests can be a big "gotcha" when programming in Perl, so I wanted to make sure I noted this here.
Code:
#!/usr/bin/perl
# HTTP HEADER
print "content-type: text/html \n\n";
# SOME VARIABLES
$x = 7;
$y = 7;
# TESTING...ONE, TWO...TESTING
if ($x == 7) {
print '$x is equal to 7!';
print "<br />";
}
if (($x == 7) || ($y == 7)) {
print '$x or $y is equal to 7!';
print "<br />";
}
if (($x == 7) && ($y == 7)) {
print '$x and $y are equal to 7!';
print "<br />";
}The Perl if/else syntax
The Perl if/else syntax is standard, I don't have any problems here:
Code:
if ($condition1)
{
# do something
}
else
{
# do the 'else' thing
}In Perl the "else if" syntax actually uses the elsif keyword. Here's some example code showing this syntax:
Code:
if ($condition1)
{
# do something
}
elsif ($condition2)
{
# do something else
}
elsif ($condition3)
{
# yada
}
else
{
# do the 'else' thing
}While I'm in the neighborhood of Perl and tests (comparisons), here's a list of Perl's numeric and string comparison/equality operators:
Code:
Numeric Test String Test
Equal == eq
Not equal != ne
Less than < lt
Greater than > gt
Less than or equal to <= le
Greater than or equal to >= ge