When is tostring called

Note that you can't override the default Object. ToString method in this way that is, your extension class in C or module in Visual Basic cannot have a parameterless method named ToString that is called in place of the original type's ToString method. You'll have to provide some other name for your parameterless ToString replacement.

When you call the ToString method on a class in the Windows Runtime, it provides the default behavior for classes that don't override ToString. This is part of the support that the. NET Framework provides a default behavior for these methods. Starting with. NET Framework 4. ToString on a Windows Runtime object before falling back to the default implementation of Object.

Starting with Windows 8. ToString , provides basic formatting support comparable to that provided by Object. To prevent ambiguity, you should not implement IStringable on managed types. The common language runtime automatically routes calls from IStringable. ToString to Object. ToString if IStringable is not implemented on the managed object.

Because the common language runtime auto-implements IStringable for all managed types in Windows Store apps, we recommend that you do not provide your own IStringable implementation. If you do choose to implement IStringable in a public managed type that's exported in a Windows Runtime component, the following restrictions apply:. You can define the IStringable interface only in a "class implements" relationship, as follows:.

You cannot implement IStringable on an interface. You cannot declare a parameter to be of type IStringable. IStringable cannot be the return type of a method, property, or field. You cannot hide your IStringable implementation from base classes by using a method definition such as the following:.

Instead, the IStringable. ToString implementation must always override the base class implementation. You can hide a ToString implementation only by invoking it on a strongly typed class instance. Note that under a variety of conditions, calls from native code to a managed type that implements IStringable or hides its ToString implementation can produce unexpected behavior.

When you implement your own types, you should override the ToString method to return values that are meaningful for those types. Derived classes that require more control over formatting than ToString provides can implement the IFormattable interface. Its ToString String, IFormatProvider method enables you to define format strings that control formatting and to use an IFormatProvider object that can provide for culture-specific formatting. Overrides of the ToString method should follow these guidelines:.

The returned string should be as short as possible so that it is suitable for display by a debugger. Your ToString override should not return Empty or a null string.

Your ToString override should not throw an exception. If the string representation of an instance is culture-sensitive or can be formatted in multiple ways, implement the IFormattable interface. If the returned string includes sensitive information, you should first demand an appropriate permission. If the demand succeeds, you can return the sensitive information; otherwise, you should return a string that excludes the sensitive information.

TECH" ;. Previous Java. Short toString method in Java with Examples. Next Assigning values to static final variables in Java. Recommended Articles. Article Contributed By :. Easy Normal Medium Hard Expert. Writing code in comment? Please use ide.

Load Comments. What's New. Most popular in Java. More related articles in Java. We use cookies to ensure you have the best browsing experience on our website. The toString method returns a string representing the object. Every object has a toString method that is automatically called when the object is to be represented as a text value or when an object is referred to in a manner in which a string is expected.

By default, the toString method is inherited by every object descended from Object. If this method is not overridden in a custom object, toString returns " [object type] ", where type is the object type. The following code illustrates this:. Note: Starting in JavaScript 1. See Using toString to detect object class.