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=== Conditional and looping constructs ===
=== Conditional and looping constructs ===
Perl has most of the usual conditional and looping constructs. As of Perl 5.10, it even has a case/switch statement (spelled given /when ). See Switch Statements in perlsyn for more details.
Perl has most of the usual conditional and looping constructs. As of Perl 5.10, it even has a case/switch statement (spelled '''given''' /'''when''' ). See [http://perldoc.perl.org/perlsyn.html#Switch-Statements Switch Statements in perlsyn] for more details.
The conditions can be any Perl expression. See the list of operators in the next section for information on comparison and boolean logic operators, which are commonly used in conditional statements.
The conditions can be any Perl expression. See the list of operators in the next section for information on comparison and boolean logic operators, which are commonly used in conditional statements.
}
}
This is provided as a more readable version of if (!condition).
This is provided as a more readable version of '''if (!condition)'''.
Note that the braces are required in Perl, even if you've only got one line in the block. However, there is a clever way of making your one-line conditional blocks more English like:
Note that the braces are required in Perl, even if you've only got one line in the block. However, there is a clever way of making your one-line conditional blocks more English like:
}
}
There's also a negated version, for the same reason we have unless :
There's also a negated version, for the same reason we have '''unless''' :
until ( condition ) {
until ( condition ) {
}
}
You can also use while in a post-condition:
You can also use '''while''' in a post-condition:
print "LA LA LA\n" while 1; # loops forever
print "LA LA LA\n" while 1; # loops forever
}
}
The C style for loop is rarely needed in Perl since Perl provides the more friendly list scanning foreach loop.
The C style for loop is rarely needed in Perl since Perl provides the more friendly list scanning '''foreach''' loop.
==== foreach ====
==== foreach ====
}
}
The foreach keyword is actually a synonym for the for keyword. See Foreach Loops in perlsyn.
The '''foreach''' keyword is actually a synonym for the for keyword. See [http://perldoc.perl.org/perlsyn.html#Foreach-Loops Foreach Loops in perlsyn].
For more detail on looping constructs (and some that weren't mentioned in this overview) see [http://perldoc.perl.org/perlsyn.html perlsyn].
=== Builtin operators and functions ===
=== Builtin operators and functions ===
