Groovy example source code file (PowerOperatorsTest.groovy)

This example Groovy source code file (PowerOperatorsTest.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

bigdecimal, bigdecimal, biginteger, biginteger, double, double, groovytestcase, integer, integer, long, poweroperatorstest

The Groovy PowerOperatorsTest.groovy source code

package groovy.operator

/** 
 * Test Math Power Operation in Classic/New Groovy
 * 
 * @author Pilho Kim
 * @version $Revision: 4996 $
 */
class PowerOperatorsTest 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)
    }

    void testPowerConversions() {
        assert (2**5).class == Integer
        assert (2l**5).class == Long
        assert (2.0d**5).class == Integer
        assert (2.1d**5).class == Double
        assert (new BigInteger("2")**5).class == BigInteger
        assert (new BigDecimal("2")**5).class == BigDecimal

        assert (2**-1).class == Double
        assert (2l**-1).class == Double
        assert (2.0d**-1).class == Double
        assert (new BigInteger("2")**-1).class == Double
        assert (new BigDecimal("2")**-1).class == Double

        assert (2**31).class == BigInteger
        assert (2l**63).class == BigInteger
        assert (2**31) == new BigInteger("2").pow(31)
        assert (2l**63) == new BigInteger("2").pow(63)
    }
}