Code inspection: Nested string interpolation can be inlined

This inspection reports an interpolated string inserted inside another interpolated string. This usually happens when a nested $"..." is used only to produce text for the outer interpolation.

Example

The nested interpolation can be merged into the containing string, which makes the code shorter and easier to read.

string message = $"User: {$"{firstName} {lastName}"}";

string message = $"User: {firstName} {lastName}";

Quick-fix

Merge the nested string interpolation with the containing interpolation.

29 March 2026