Null object: Difference between revisions
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NilClass |
NilClass |
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</pre> |
</pre> |
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=={{header|Rust}}== |
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<lang rust>// If an option may return null - or nothing - in Rust, it's wrapped |
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// in an Optional which may return either the type of object specified |
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// in <> or None. We can check this using .is_some() and .is_none() on |
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// the Option. |
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fn check_number(num: &Option<u8>) { |
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if num.is_none() { |
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println!("Number is: None"); |
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} else { |
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println!("Number is: {}", num.unwrap()); |
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} |
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} |
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fn main() { |
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let mut possible_number: Option<u8> = None; |
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check_number(&possible_number); |
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possible_number = Some(31); |
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check_number(&possible_number); |
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}</lang> |
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=={{header|Scala}}== |
=={{header|Scala}}== |