NAME

reverse - flip a string or a list

SYNOPSIS

reverse LIST

DESCRIPTION

In list context, returns a list value consisting of the elements of LIST in the opposite order. In scalar context, concatenates the elements of LIST, and returns a string value consisting of those bytes, but in the opposite order. 

    print reverse <>;           # line tac, last line first


    undef $/;                   # for efficiency of <>
    print scalar reverse <>;    # byte tac, last line tsrif

This operator is also handy for inverting a hash, although there are some caveats. If a value is duplicated in the original hash, only one of those can be represented as a key in the inverted hash. Also, this has to unwind one hash and build a whole new one, which may take some time on a large hash. 

    %by_name = reverse %by_address;     # Invert the hash

DISCLAIMER

We are painfully aware that these documents may contain incorrect links and misformatted HTML. Such bugs lie in the automatic translation process that automatically created the hundreds and hundreds of separate documents that you find here. Please do not report link or formatting bugs, because we cannot fix per-document problems. The only bug reports that will help us are those that supply working patches to the installhtml or pod2html programs, or to the Pod::HTML module itself, for which I and the entire Perl community will shower you with thanks and praises.

If rather than formatting bugs, you encounter substantive content errors in these documents, such as mistakes in the explanations or code, please use the perlbug utility included with the Perl distribution.

--Tom Christiansen, Perl Documentation Compiler and Editor

Return to the Perl Documentation Index.
Return to the Perl Home Page.