Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
705 views
in Technique[技术] by (71.8m points)

arrays - Is there a Perl shortcut to count the number of matches in a string?

Suppose I have:

my $string = "one.two.three.four";

How should I play with context to get the number of times the pattern found a match (3)? Can this be done using a one-liner?

I tried this:

my ($number) = scalar($string=~/./gi);

I thought that by putting parentheses around $number, I'd force array context, and by the use of scalar, I'd get the count. However, all I get is 1.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

That puts the regex itself in scalar context, which isn't what you want. Instead, put the regex in list context (to get the number of matches) and put that into scalar context.

 my $number = () = $string =~ /./gi;

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...