What does "last" do in Perl?
perl
Solution
Available uses for `last` command:
last LABEL
last EXPR
last
According to Perl's documentation:
The `last` command is like the `break` statement in C (as used in loops); it immediately exits the loop in question. If the LABEL is omitted, the command refers to the innermost enclosing loop. The last EXPR form, available starting in Perl 5.18.0, allows a label name to be computed at run time, and is otherwise identical to last LABEL . The continue block, if any, is not executed:
LINE: while (<STDIN>) {
last LINE if /^$/; # exit when done with header
#...
}
last cannot be used to exit a block that returns a value such as eval {} , sub {} , or do {} , and should not be used to exit a grep or map operation. Note that a block by itself is semantically identical to a loop that executes once. Thus last can be used to effect an early exit out of such a block.
Problem
In the code below, what does `last` do in the while loop? I get that if the `$matrix[$i][$j]{pointer}` variable equals `"none"` it calls `last` but what does it do? Also why does the $matrix variable include score and pointer using curly braces? `{score}`, I read this as the 3rd dimension in an array, but is this something else? Couldn't find anything on google about this. Thanks! ``` my @matrix; $matrix[0][0]{score} = 0; $matrix[0][0]{pointer} = "none"; #populate $matrix with more stuff while (1) { last if $matrix[$i][$j]{pointer} eq "none"; #<-what is this "last" doing? #do some more stuff here } ```