Gotchas
We’ll see a number of nice Groovy capabilities throughout this book, but some “gotchas“ do exist, ranging from minor annoyances to potential surprises. In the following sections, we’ll explore a few of them.
Groovy’s == Is Equal to Java’s equals
== and equals are a source of confusion in Java, and Groovy adds to the confusion. Groovy maps the == operator to the equals method in Java. What if we want to actually perform the reference equals (the original ==, that is)? We have to use is in Groovy for that. Let’s understand the difference via an example:
| GroovyForJavaEyes/Equals.groovy | |
| | str1 = 'hello' |
| | str2 = str1 |
| | str3 = new String('hello') |
| | str4 = 'Hello' |
| | |
| | println "str1 == str2: ${str1 == str2}" |
| | println "str1 == str3: ... |
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