CA1514: Avoid redundant length argument

Property	Value
Rule ID	CA1514
Title	Avoid redundant length argument
Category	Maintainability
Fix is breaking or non-breaking	Non-breaking
Enabled by default in .NET 9	As suggestion

Cause

A redundant length argument is passed to String.Substring, Span<T>.Slice, ReadOnlySpan<T>.Slice, or Memory<T>.Slice when slicing to the end of a string or buffer.

An explicitly calculated length argument can be error-prone and is unnecessary when you're slicing to the end of a string or buffer.

Code that omits the length argument is more readable and maintainable.

Remove the length argument.

The following code snippet shows a violation of CA1514:

string message = "Hello World!";
string world = message.Substring(6, message.Length - 6); // "World!"

Dim message As String = "Hello World!"
Dim world As String = message.Substring(6, message.Length - 6) ' "World!"

The following code snippet fixes the violation:

string message = "Hello World!";
string world = message.Substring(6); // "World!"

Dim message As String = "Hello World!"
Dim world As String = message.Substring(6) ' "World!"

It's safe to suppress a violation of this rule if you're not concerned about the maintainability of your code.

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable CA1514
// The code that's violating the rule is on this line.
#pragma warning restore CA1514

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.{cs,vb}]
dotnet_diagnostic.CA1514.severity = none