语法

// a standalone single line comment
println "hello" // a comment till the end of the line

/* a standalone multiline comment
   spanning two lines */
println "hello" /* a multiline comment starting
                   at the end of a statement */
println 1 /* one */ + 2 /* two */

/**
 * A Class description
 */
class Person {
    /** the name of the person */
    String name

    /**
     * Creates a greeting method for a certain person.
     *
     * @param otherPerson the person to greet
     * @return a greeting message
     */
    String greet(String otherPerson) {
       "Hello ${otherPerson}"
    }
}

/**@
 * Some class groovydoc for Foo
 */
class Foo {
    /**@
     * Some method groovydoc for bar
     */
    void bar() {
    }
}

assert Foo.class.groovydoc.content.contains('Some class groovydoc for Foo') (1)
assert Foo.class.getMethod('bar', new Class[0]).groovydoc.content.contains('Some method groovydoc for bar') (2)

#!/usr/bin/env groovy
println "Hello from the shebang line"

def name
def item3
def with_underscore
def $dollarStart

def 3tier
def a+b
def a#b

foo.as
foo.assert
foo.break
foo.case
foo.catch

def map = [:]

map."an identifier with a space and double quotes" = "ALLOWED"
map.'with-dash-signs-and-single-quotes' = "ALLOWED"

assert map."an identifier with a space and double quotes" == "ALLOWED"
assert map.'with-dash-signs-and-single-quotes' == "ALLOWED"

map.'single quote'
map."double quote"
map.'''triple single quote'''
map."""triple double quote"""
map./slashy string/
map.$/dollar slashy string/$

def firstname = "Homer"
map."Simpson-${firstname}" = "Homer Simpson"

assert map.'Simpson-Homer' == "Homer Simpson"

'a single-quoted string'

assert 'ab' == 'a' + 'b'

'''a triple-single-quoted string'''

def aMultilineString = '''line one
line two
line three'''

def startingAndEndingWithANewline = '''
line one
line two
line three
'''

def strippedFirstNewline = '''\
line one
line two
line three
'''

assert !strippedFirstNewline.startsWith('\n')

"a double-quoted string"

def name = 'Groovy'
def template = """
    Dear Mr ${name},

    You're the winner of the lottery!

    Yours sincerly,

    Dave
"""

assert template.toString().contains('Groovy')

def fooPattern = /.*foo.*/
assert fooPattern == '.*foo.*'

def escapeSlash = /The character \/ is a forward slash/
assert escapeSlash == 'The character / is a forward slash'

def multilineSlashy = /one
    two
    three/

assert multilineSlashy.contains('\n')

def color = 'blue'
def interpolatedSlashy = /a ${color} car/

assert interpolatedSlashy == 'a blue car'

def name = "Guillaume"
def date = "April, 1st"

def dollarSlashy = $/
    Hello $name,
    today we're ${date}.

    $ dollar sign
    $$ escaped dollar sign
    \ backslash
    / forward slash
    $/ escaped forward slash
    $$$/ escaped opening dollar slashy
    $/$$ escaped closing dollar slashy
/$

assert [
    'Guillaume',
    'April, 1st',
    '$ dollar sign',
    '$ escaped dollar sign',
    '\\ backslash',
    '/ forward slash',
    '/ escaped forward slash',
    '$/ escaped opening dollar slashy',
    '/$ escaped closing dollar slashy'
].every { dollarSlashy.contains(it) }

char c1 = 'A' (1)
assert c1 instanceof Character

def c2 = 'B' as char (2)
assert c2 instanceof Character

def c3 = (char)'C' (3)
assert c3 instanceof Character

// primitive types
byte  b = 1
char  c = 2
short s = 3
int   i = 4
long  l = 5

// infinite precision
BigInteger bi =  6

def a = 1
assert a instanceof Integer

// Integer.MAX_VALUE
def b = 2147483647
assert b instanceof Integer

// Integer.MAX_VALUE + 1
def c = 2147483648
assert c instanceof Long

// Long.MAX_VALUE
def d = 9223372036854775807
assert d instanceof Long

// Long.MAX_VALUE + 1
def e = 9223372036854775808
assert e instanceof BigInteger

def na = -1
assert na instanceof Integer

// Integer.MIN_VALUE
def nb = -2147483648
assert nb instanceof Integer

// Integer.MIN_VALUE - 1
def nc = -2147483649
assert nc instanceof Long

// Long.MIN_VALUE
def nd = -9223372036854775808
assert nd instanceof Long

// Long.MIN_VALUE - 1
def ne = -9223372036854775809
assert ne instanceof BigInteger

// primitive types
float  f = 1.234
double d = 2.345

// infinite precision
BigDecimal bd =  3.456

assert 1e3  ==  1_000.0
assert 2E4  == 20_000.0
assert 3e+1 ==     30.0
assert 4E-2 ==      0.04
assert 5e-1 ==      0.5

long creditCardNumber = 1234_5678_9012_3456L
long socialSecurityNumbers = 999_99_9999L
double monetaryAmount = 12_345_132.12
long hexBytes = 0xFF_EC_DE_5E
long hexWords = 0xFFEC_DE5E
long maxLong = 0x7fff_ffff_ffff_ffffL
long alsoMaxLong = 9_223_372_036_854_775_807L
long bytes = 0b11010010_01101001_10010100_10010010

assert 42I == Integer.valueOf('42')
assert 42i == Integer.valueOf('42') // lowercase i more readable
assert 123L == Long.valueOf("123") // uppercase L more readable
assert 2147483648 == Long.valueOf('2147483648') // Long type used, value too large for an Integer
assert 456G == new BigInteger('456')
assert 456g == new BigInteger('456')
assert 123.45 == new BigDecimal('123.45') // default BigDecimal type used
assert .321 == new BigDecimal('.321')
assert 1.200065D == Double.valueOf('1.200065')
assert 1.234F == Float.valueOf('1.234')
assert 1.23E23D == Double.valueOf('1.23E23')
assert 0b1111L.class == Long // binary
assert 0xFFi.class == Integer // hexadecimal
assert 034G.class == BigInteger // octal

def primes = new int[] {2, 3, 5, 7, 11}
assert primes.size() == 5 && primes.sum() == 28
assert primes.class.name == '[I'

def pets = new String[] {'cat', 'dog'}
assert pets.size() == 2 && pets.sum() == 'catdog'
assert pets.class.name == '[Ljava.lang.String;'

// traditional Groovy alternative still supported
String[] groovyBooks = [ 'Groovy in Action', 'Making Java Groovy' ]
assert groovyBooks.every{ it.contains('Groovy') }