Posts Tagged ‘String’

Test if a string is an integer

Groovy provides a string function isInteger() that tests if a string is an integer: def num1 = "12345" def num2 = "123.45" assert num1.isInteger() assert !num2.isInteger()

Check if a list contains a value

A Groovy list is a Java ArrayList which provides a contains() method. def list = [1,3,5] assert list.contains(3) assert !list.contains(4) Alternatively you can use Groovy’s in operator. def list = [1,3,5] assert 3 in list assert !(4 in list) Note that this method may provide unexpected results when comparing Strings and GStrings. For example, the [...]

Get the hash of a string

You can get a quick hash code for a string (and all other objects) in Groovy by simply calling it’s hashCode() method. def message = ‘hello’ println message.hashCode() Which prints 99162322

Generate a UUID

To generate UUIDs we use the java.util.UUID class import java.util.UUID   uuid = UUID.randomUUID() For a slightly nicer syntax we can use the a static import of the randomUUID() method import static java.util.UUID.randomUUID   uuid = randomUUID() Note that in both cases the randomUUID() method returns an instance of java.util.UUID. If you need an actual [...]

Remove the first character of a string

To remove the first character of a string we can use Groovy’s range index notation. def name = ‘GROOVY’ def substring = name[1..-1]   assert substring == ‘ROOVY’

Remove the last character of a string

To remove the last character of a string we can use Groovy’s range index notation. def name = ‘GROOVY’ def substring = name[0..-2]   assert substring == ‘GROOV’

Find the last character of a string

To find the last character of a string we can use Groovy’s negative index syntax. def name = ‘GROOVY’ def lastChar = name[-1]   assert lastChar == ‘Y’

Test for an empty string

In Groovy, a null or empty string evaluates to a boolean false value, so we can take advantage of this in our code: def s = ” if (s) { println "We’ve got a non empty string!" } else { println ‘String is either null or empty’ } Which, in this case prints: String is [...]

Repeat a string

You can repeat a string in groovy using the multiply function: def divider = ‘-’.multiply(10) Or use the standard multiply operator: def divider = ‘-’ * 10

Create a multiline string

Multi-line strings are created by using the triple double quote. def s = """This is an example of a multi-line String """   println s This is also known as a heredoc string.