Groovy Goodness: Using def to Define a Variable

Groovy has the def keyword to replace a type name when we declare a variable. Basically it means we don't really want to define the type ourselves or we want to change the type along the ride.

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def myvar = 42 assert myvar instanceof Integer   myvar = 'I am a String'  // String assignment changes type. assert myvar instanceof String   String s = 'I am String' assert s instanceof String   s = new Integer(100)  // Surprise, surprise, value is converted to String! assert s instanceof String   int i = 42 assert i instanceof Integer   try {     i = 'test'  // Cannot assign String value to Integer. } catch (e) {     assert e instanceof org.codehaus.groovy.runtime.typehandling.GroovyCastException }