It evaluates the code that you give it. It can be used when you need to
create code on the fly, like this...
my $cmd = 'print';
my $arg = 'Hello World';
eval("$cmd '$arg'");
This is useful for allowing a user to pass code to the program (for whatever
reason).
The other use it to trap errors.
my $this = 1;
my $that = 2;
eval {
if ($this != $that) {
die "They don't match!";
}
};
print $@;
In this case the "die" doesn't terminate the program, it only terminates the
eval. And $@ stores the error message that was "thrown" in the eval. So
this prints the error message without abnormally terminating the program.
This is akin to the try/catch blocks in other languages (the Errors gives
you try/catch functionality by using eval).
Hope that helps.
Rob
-----Original Message-----
From: Mallik [mailto:[EMAIL PROTECTED]
Sent: Thursday, January 29, 2004 7:26 AM
To: Perl Beginners
Subject: What is eval?
Can anybody explain the functionality of eval in brief?
Thanks in advance,
Mallik.
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