Select Code to Download

$hash{'a'};
print exists $hash{'a'}?'yes':'no';
#no

$hash{'a'}=1;
print exists $hash{'a'}?'yes':'no';
#yes

$hash{'a'}=$hash{'a'};
print exists $hash{'a'}?'yes':'no';
#yes

sub foo{$_[0]}
foo($hash{'a'});
print exists $hash{'a'}?'yes':'no';
#no

sub foo{$_[0]=1}
foo($hash{'a'});
print exists $hash{'a'}?'yes':'no';
#yes

sub foo{$_[0]=$_[0]}
foo($hash{'a'});
print exists $hash{'a'}?'yes':'no';
#yes

sub foo{
    for($_[0]){
...
foo($hash{'a'});
print exists $hash{'a'}?'yes':'no';
#no

sub foo{
    for($_[0]){
...
foo($hash{'a'});
print exists $hash{'a'}?'yes':'no';
#yes

for($hash{'a'}){
}
print exists $hash{'a'}?'yes':'no';
#yes

sub foo{
    for($_[0]){
...
foo($hash{'a'});
print exists $hash{'a'}?'yes':'no';
#no