Re: Testing for key/value match

It seems to me you're misunderstanding how hashes work.
Keys in a hash are unique. What this means is that you can't have two or more identical keys with different values.
If you want to test whether a certain key exists and has the value you expect, you can do this

if (defined $foo{'bar'} and $foo{'bar'} eq 'baz'){

}
[download]

--perlplexer

Comment on Re: Testing for key/value match Download Code

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Re: Re: Testing for key/value match by particle (Vicar) on May 10, 2002 at 15:01 UTC
If you want to test whether a certain key exists and has the value you expect, you can do this `if (defined $foo{'bar'} and $foo{'bar'} eq 'baz'){ }` [download] perhaps you mean exists? `if (exists $foo{'bar'} and $foo{'bar'} eq 'baz'){ }` [download] reminder to all: in an array or hash lookup, defined tests for definedness of the value of the array index or hash key, which may not be what you mean. use exists to test whether the array index or hash key is present. ~Particle accelerates	[reply] [d/l] [select]
Re: Re: Re: Testing for key/value match by perlplexer (Hermit) on May 10, 2002 at 15:10 UTC
No, defined() is what I wanted to say. The value may exist but may be undefined, in which case the 'eq' will produce a warning. --perlplexer	[reply]
Re^4: Testing for key/value match by particle (Vicar) on May 10, 2002 at 15:53 UTC
so if undefined is what you expect, it looks like none of these solutions will work. ~Particle accelerates	[reply]