Difference between revisions of "Perl"
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Line 10: | Line 10: | ||
<syntaxhighlight lang=Perl> | <syntaxhighlight lang=Perl> | ||
use Data::Dumper; | use Data::Dumper; | ||
+ | print Dumper($variable); | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | if-then-else: | ||
+ | <syntaxhighlight lang=Perl> | ||
+ | if < expr > { | ||
+ | <codeblock> | ||
+ | } elsif < expr ) { | ||
+ | <codeblock> | ||
+ | } else { | ||
+ | <codeblock> | ||
+ | } | ||
print Dumper($variable); | print Dumper($variable); | ||
</syntaxhighlight> | </syntaxhighlight> |
Revision as of 11:50, 19 March 2018
I'm leaving Perl, traded it for Python. Some shortcuts I'd like to remember
WARNING
Checking existence of a hash element creates the parent keys (autovivification). Always check top-down.
Things that do work
Print out the contents of $variable in a structured format.
use Data::Dumper;
print Dumper($variable);
if-then-else:
if < expr > {
<codeblock>
} elsif < expr ) {
<codeblock>
} else {
<codeblock>
}
print Dumper($variable);
- $var += <value>
- Add <value> to $var (works for -, *, / too)
- $string .= $addstring
- Concatenate $string and $addstring
- $string =~ s/<regexp>/<newvalue>/[g]
- Substitute <regexp> with <newvalue> in $string. The g modifier makes the all occurrences of <regexp> are substituted.
- $newstring = substr($string,start,length)
- Return substring of $string
- sprintf(format,$string)
- Return formatted string. format is e.g. "%.3f". Check Python:Strings#Advanced for all formats.
Searching is explained in Regular Expressions.