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Do not use the same variable name in two scopes where one scope is contained in another. For example,

• A lexical variable should not share the name of a package variable if the lexical variable is in a subscope of the global variable.
• A block should not declare a lexical variable with the same name as a lexical variable declared in any block that contains it.

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This noncompliant code example declares the errmsg identifier at file scope and reuses the same identifier to declare a string that is private in the report_error() subroutine. Consequently, the program prints "The error is Local error" , rather than "The error is Global error.".

$errmsg = "Global error";

sub report_error {
  my $errmsg = shift(@_);
  # ...
  print "The error is $errmsg\n";
};

report_error("Local error");

...

$global_error_msg = "Global error";

sub report_error {
  my $local_error_msg = shift(@_);
  # ...
  print "The error is $local_error_msg\n";
};

report_error("Local error");

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