大名鼎鼎的java动态脚本语言。已经通过了sun的认证

				/** 				 * Test Math Power Operation in Classic/New Groovy				 * 				 * @author Pilho Kim				 * @version $Revision: 1.3 $				 */				class PowerOperationTest extends GroovyTestCase {								    void testConstantPowerOperation() {				        assert 2**5 == 32				        assert -2**5 == -32				        assert 3**4 == 81				        assert -3**4 == -81				        assert 3**-4 == 3.power(-4)				        assert -3**-4 == -3.power(-4)				        assert 7**2 - 7*3 + 2 == 30         //  49 - 21 + 2 = 30				        assert -7**2 - 7*3 + 2 == -68       // -49 - 21 + 2 = -68				        assert -(7**2) - 7*3 + 2 == -68     // -49 - 21 + 2 = -68				        assert (-7)**2 - 7*3 + 2 == 30     //  49 - 21 + 2 = 30				    }								    void testPowerOperation() {				        def x = 9				        --x				        assert x == 8				        println(--x)				        assert x == 7				        println(--x)				        assert x == 6				        println((--x)**3)				        assert x == 5				        assert (--x)**3 == 64				        assert (-x**3) == -64				        assert x == 4				        assert (++x)**3 == 125				        assert x == 5				        assert (x++)**3 == 125				        assert x == 6				        println((x++)**3)				        assert x == 7				        println(x)				        println("${x**2}")				        println("${-x**2}")				        assert x == 7				        println("${(--x)**2}")				        assert x == 6				        assert (--x)**2 + x*2 - 1 == 34      // 5**2 + 5*2 - 1 = 34				        assert x == 5				        assert (x--)**2 + x*2 - 1 == 32      // 5**2 + 4*2 - 1 = 32				        assert x == 4				    }								    void testConstantPowerAssignmentOperation() {				        def x = 5				        x **= 2				        assert x == 25				        assert x**2 == 625				        assert -x**2 != 625				        assert -x**2 == -625				    }								    void testPowerAssignmentOperation() {				        def x = 5				        def y = 2				        x **= y				        assert x == 25				        assert x**y == 625				        assert x**-1 == 1/25				        assert x**-y == 1/625				        assert x**-y == x**(-y)				    }				}