AssertionError (Java SE 12 & JDK 12 )
Keywords: java.lang.AssertionError class

Module java.base
Package java.lang

## Class AssertionError

- java.lang.Object
- - java.lang.Throwable
  - - java.lang.Error
    - - java.lang.AssertionError

- All Implemented Interfaces:
    `Serializable`

      public class AssertionError
      extends Error

  Thrown to indicate that an assertion has failed.

  The seven one-argument public constructors provided by this class ensure that the assertion error returned by the invocation:

           new AssertionError(expression)

  has as its detail message the string conversion of expression (as defined in section 15.18.1.1 of The Java™ Language Specification), regardless of the type of expression.
  Since:
    1.4
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `AssertionError()` | Constructs an AssertionError with no detail message.
    `AssertionError​(boolean detailMessage)` | Constructs an AssertionError with its detail message derived from the specified `boolean`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(char detailMessage)` | Constructs an AssertionError with its detail message derived from the specified `char`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(double detailMessage)` | Constructs an AssertionError with its detail message derived from the specified `double`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(float detailMessage)` | Constructs an AssertionError with its detail message derived from the specified `float`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(int detailMessage)` | Constructs an AssertionError with its detail message derived from the specified `int`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(long detailMessage)` | Constructs an AssertionError with its detail message derived from the specified `long`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(Object detailMessage)` | Constructs an AssertionError with its detail message derived from the specified object, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
    `AssertionError​(String message, Throwable cause)` | Constructs a new `AssertionError` with the specified detail message and cause.

  - ### Method Summary

    - ### Methods declared in class java.lang.Throwable

      `addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString`

    - ### Methods declared in class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### AssertionError

          public AssertionError()

      Constructs an AssertionError with no detail message.

    - #### AssertionError

          public AssertionError​(Object detailMessage)

      Constructs an AssertionError with its detail message derived from the specified object, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

      If the specified object is an instance of `Throwable`, it becomes the cause of the newly constructed assertion error.

      Parameters:
        `detailMessage` - value to be used in constructing detail message
      See Also:
        `Throwable.getCause()`

    - #### AssertionError

          public AssertionError​(boolean detailMessage)

      Constructs an AssertionError with its detail message derived from the specified `boolean`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
      Parameters:
        `detailMessage` - value to be used in constructing detail message

    - #### AssertionError

          public AssertionError​(char detailMessage)

      Constructs an AssertionError with its detail message derived from the specified `char`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
      Parameters:
        `detailMessage` - value to be used in constructing detail message

    - #### AssertionError

          public AssertionError​(int detailMessage)

      Constructs an AssertionError with its detail message derived from the specified `int`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
      Parameters:
        `detailMessage` - value to be used in constructing detail message

    - #### AssertionError

          public AssertionError​(long detailMessage)

      Constructs an AssertionError with its detail message derived from the specified `long`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
      Parameters:
        `detailMessage` - value to be used in constructing detail message

    - #### AssertionError

          public AssertionError​(float detailMessage)

      Constructs an AssertionError with its detail message derived from the specified `float`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
      Parameters:
        `detailMessage` - value to be used in constructing detail message

    - #### AssertionError

          public AssertionError​(double detailMessage)

      Constructs an AssertionError with its detail message derived from the specified `double`, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
      Parameters:
        `detailMessage` - value to be used in constructing detail message

    - #### AssertionError

          public AssertionError​(String message,
                                Throwable cause)

      Constructs a new `AssertionError` with the specified detail message and cause.

      Note that the detail message associated with `cause` is not automatically incorporated in this error's detail message.

      Parameters:
        `message` - the detail message, may be `null`
        `cause` - the cause, may be `null`
      Since:
        1.7