Using "$" in Groovy
I See { } Are Used for Closures, and Then I Believe When a $ Is Put in Front of Braces, It Is Simply Doing a Variable Substitution Within a String. I Can't...
I see { } are used for closures, and then I believe when a $ is put in front of braces, it is simply doing a variable substitution within a string. I can't find the documentation on how the $ works in the reference ... hard to search on it unfortunately, and the Groovy String documentation is lacking in introducing this. Can you please point me to the documentation and/or explain the "$" operator in Groovy -- how all it can be used? Does Grails extend it at all beyond Groovy?
4 Answers
In a GString (groovy string), any valid Groovy expression can be enclosed in the ${...} including method calls etc.
This is detailed in the following page.
Grails does not extend the usage of $ beyond Groovy. Here are two practical usages of $
String Interpolation
Within a GString you can use $ without {} to evaluate a property path, e.g.
def date = new Date()
println "The time is $date.time"
If you want to evaluate an expression which is more complex than a property path, you must use ${}, e.g.
println "The time is ${new Date().getTime()}"
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