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Programming Perl, 3rd Edition
book

Programming Perl, 3rd Edition

by Larry Wall, Tom Christiansen, Jon Orwant
July 2000
Intermediate to advanced content levelIntermediate to advanced
1104 pages
35h 1m
English
O'Reilly Media, Inc.
Content preview from Programming Perl, 3rd Edition

Equality Operators

The equality operators listed in Table 3.6 are much like the relational operators.

Table 3-6. Equality Operators

NumericStringMeaning
==eqEqual to
!=neNot equal to
<=>cmpComparison, with signed result

The equal and not-equal operators return 1 for true and "" for false (just as the relational operators do). The <=> and cmp operators return -1 if the left operand is less than the right operand, 0 if they are equal, and +1 if the left operand is greater than the right. Although the equality operators appear to be similar to the relational operators, they do have a lower precedence level, so $a < $b <=> $c < $d is syntactically valid.

For reasons that are apparent to anyone who has seen Star Wars, the <=> operator is known as the "spaceship" operator.

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Publisher Resources

ISBN: 0596000278Supplemental ContentErrata