f_map

来自「source of perl for linux application,」· 代码 · 共 30 行

#!perl
# examples shamelessly snatched from perldoc -f map

# translates a list of numbers to the corresponding characters.
@chars = map(chr, @nums);

%hash = map { getkey($_) => $_ } @array;

{
    %hash = ();
    foreach $_ (@array) {
	$hash{getkey($_)} = $_;
    }
}

#%hash = map {  "\L$_", 1  } @array;  # perl guesses EXPR.  wrong
%hash = map { +"\L$_", 1  } @array;  # perl guesses BLOCK. right

%hash = map { ("\L$_", 1) } @array;  # this also works

%hash = map {  lc($_), 1  } @array;  # as does this.

%hash = map +( lc($_), 1 ), @array;  # this is EXPR and works!

%hash = map  ( lc($_), 1 ), @array;  # evaluates to (1, @array)

@hashes = map +{ lc($_), 1 }, @array # EXPR, so needs , at end