In Groovy, the size of a hash can be found using the size() method. Here's an example:
def map = [name: 'John', age: 30, city: 'New York']
println "Size of map: ${map.size()}"
Output:
Size of map: 3
In the above code, we first define a map hash with three key-value pairs. We then call the size() method on the map variable to get the size of the hash, which is 3.
Similarly, if you want to get the size of an empty hash, you can use the size() method without any argument as shown in the following example:
def emptyMap = [:]
println "Size of empty map: ${emptyMap.size()}"
Output:
Size of empty map: 0
In this case, since the emptyMap hash is empty, its size is 0.