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Like most algorithmic programming languages, Perl has a number of looping structures.[65] The while loop repeats a block of code as long as a condition is true:
[65]Every programmer eventually creates an infinite loop by accident. If your program keeps running and running, though, you can generally stop it in the same way you'd stop any other program on your system. Often, typing Control-C will stop a runaway program; check with your system's documentation to be sure.
$count = 0;
while ($count < 10) {
$count += 1;
print "count is now $count\n"; # Gives values from 1 to 10
}As always in Perl, the truth value here works like the truth value in the if test. Also like the if control structure, the block curly braces are required. The conditional expression is evaluated before the first iteration, so the loop may be skipped completely, if the condition is initially false.
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| 2.9. The chomp Operator |  | 2.11. The undef Value |
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