Hi, i'm very new to PERL language, can you please tell me why I am not able to modify the value of $a in below code line 3? an error "Modification of a read-only value attempted at test10.pl line 3. is displayed"

 
#!/usr/bin/perl -w
$a=\100;  #initialise $a to 100 and map it to it's address
$$a=60;   # modify the value of $a 
print $$a; #should print 60

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In reply to pass by referene by mhn388

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