55 lines
1.7 KiB
Plaintext
55 lines
1.7 KiB
Plaintext
== Why is this an issue?
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The `string` type offers an indexer property that allows you to treat it as a `char` array. Therefore, if you just need to access a specific character or iterate over all of them, the `ToCharArray` call should be omitted. For these cases, not omitting makes the code harder to read and less performant as `ToCharArray` copies the characters from the `string` object into a new Unicode character array.
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The same principle applies to https://devblogs.microsoft.com/dotnet/csharp-11-preview-updates/#utf-8-string-literals[utf-8 literals types] (`ReadOnlySpan<byte>`, `Span<byte>`) and the https://learn.microsoft.com/en-us/dotnet/api/system.span-1.toarray?view=net-7.0[`ToArray`] method.
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== How to fix it
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=== Code examples
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==== Noncompliant code example
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[source,csharp,diff-id=1,diff-type=noncompliant]
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----
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string str = "some string";
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foreach (var c in str.ToCharArray()) // Noncompliant
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{
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// ...
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}
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ReadOnlySpan<byte> span = "some UTF-8 string literal"u8;
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foreach (var c in span.ToArray()) // Noncompliant
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{
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// ...
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}
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----
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==== Compliant solution
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[source,csharp,diff-id=1,diff-type=compliant]
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----
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string str = "some string";
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foreach (var c in str)
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{
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// ...
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}
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ReadOnlySpan<byte> span = "some UTF-8 string literal"u8;
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foreach (var b in span) // Compliant
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{
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// ...
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}
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----
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== Resources
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=== Documentation
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* https://learn.microsoft.com/en-us/dotnet/api/system.string.tochararray[String.ToCharArray Method]
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* https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/strings/#accessing-individual-characters[Accessing individual characters]
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* https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-11.0/utf8-string-literals[UTF-8 Strings literals]
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include::./rspecator.adoc[] |