Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
There are a number of ways, with varying efficiency: If you want a count of a certain single character (X) within a string, you can use the tr/// function like so:
$string = "ThisXlineXhasXsomeXx'sXinXit": $count = ($string =~ tr/X//); print "There are $count X charcters in the string";
This is fine if you are just looking for a single character. However, if
you are trying to count multiple character substrings within a larger
string, tr/// won't work. What you can do is wrap a
while()
loop around a global
pattern match. For example, let's count negative integers:
$string = "-9 55 48 -2 23 -76 4 14 -44"; while ($string =~ /-d+/g) { $count++ } print "There are $count negative numbers in the string";