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course 1.2.2.1

Effective use of map, sort and grep in Perl

These three operators - map, sort and grep - pack a lot of functionality. Not uncommonly, the three can be used on a single line to extract, transform and order data. Use map to initialize, distill and transform data structures. Use sort to not only order data, but also shuffle data. Finally, grep is used to extract data using a test condition. Each of these operators lends itself to idiomatic patterns, which will be discussed. As well, each of these operators can be misused and can lead to subtle bugs in your code. I'll try to point a few of these out.

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[ consider using for instead of foreach ]

1.2.2.1 Effective use of map, sort and grep in Perl

lecture notes

1 | Perl's sort, map and grep | 1.2.2.1.1

These three operators form the backbone of data analysis in Perl. Learn how to use them effectively, see typical idioms, and see how to avoid common pitfalls.

1.2.2.1.1.c1 | data.txt | Martin Krzywinski | code