PH2146.md

PH2146: Avoid calling ToString() on string type

Property	Value
Package	Philips.CodeAnalysis.MaintainabilityAnalyzers
Diagnostic ID	PH2146
Category	Maintainability
Analyzer	AvoidToStringOnStringAnalyzer
CodeFix	Yes
Severity	Info
Enabled By Default	Yes

Introduction

Calling ToString() on an expression that is already of type string is redundant and should be removed to improve code clarity and performance.

How to solve

Remove the unnecessary .ToString() call from string expressions.

Example

Code that triggers a diagnostic:

class BadExample
{
    public void BadMethod()
    {
        string str = "hello";
        string result = str.ToString(); // Redundant
        
        System.Console.WriteLine("world".ToString()); // Redundant
        
        string combined = (str + " world").ToString(); // Redundant
    }
}

And the replacement code:

class GoodExample
{
    public void GoodMethod()
    {
        string str = "hello";
        string result = str; // ToString() removed
        
        System.Console.WriteLine("world"); // ToString() removed
        
        string combined = (str + " world"); // ToString() removed
    }
}

Note: The analyzer only flags ToString() calls with no parameters. Calls like str.ToString(CultureInfo.InvariantCulture) are not flagged as they may have different behavior.

Configuration

This analyzer does not offer any special configuration. The general ways of suppressing diagnostics apply.