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| The '''spaceship operator''' is a binary ] which originated in the ] ]. ] also supports the spaceship operator. It is written <=> . Unlike traditional equality operators, which will return 1 or 0 depending on whether the arguments are equal or unequal, the spaceship operator will return 1, 0, or -1 depending on the value of the left argument relative to the right argument. If the left argument is greater than the right argument, the operator returns 1. If the left argument is less than the right argument, the operator returns -1. If the two arguments are equal, the operator returns 0. | The '''spaceship operator''' is a binary ] which originated in the ] ]. ] also supports the spaceship operator. It is written <=> . Unlike traditional equality operators, which will return 1 or 0 depending on whether the arguments are equal or unequal, the spaceship operator will return 1, 0, or -1 depending on the value of the left argument relative to the right argument. If the left argument is greater than the right argument, the operator returns 1. If the left argument is less than the right argument, the operator returns -1. If the two arguments are equal, the operator returns 0. | ||
| The spaceship operator is primarily used for comparisons in ]. It is usable for a ] as it will return 0 for equal arguments. | The spaceship operator is primarily used for comparisons in ]. It is usable for a ] as it will return 0 for equal arguments. | ||
Revision as of 02:47, 19 July 2007
The spaceship operator is a binary relational operator which originated in the Perl programming language. Ruby also supports the spaceship operator. It is written <=> . Unlike traditional equality operators, which will return 1 or 0 depending on whether the arguments are equal or unequal, the spaceship operator will return 1, 0, or -1 depending on the value of the left argument relative to the right argument. If the left argument is greater than the right argument, the operator returns 1. If the left argument is less than the right argument, the operator returns -1. If the two arguments are equal, the operator returns 0.
The spaceship operator is primarily used for comparisons in sorting. It is usable for a stable sort as it will return 0 for equal arguments.
The spaceship operator takes its name because it looks like a small flying saucer as ASCII art. The term is now commonly used and the operator is referred by the name within the actual perldocs.
Example
$a = 5 <=> 7; # $a is set to -1
$a = 7 <=> 5; # $a is set to 1
$a = 6 <=> 6; # $a is set to 0
External Links
Reference to the properties of the operator within perldoc
Reference to the actual term within perldoc
Category: