Groovy Puzzlers S04: The Bytecode Bites Back at Gr8Conf US 2017
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The document contains a series of programming and coding snippets that illustrate various concepts, particularly in Groovy. It presents examples of how different data structures and methods operate, while also integrating humorous references and anecdotes related to coding practices. Additionally, it invites readers to engage with the content through feedback channels.
![def comments = ['FRIST!', 'YAS!']
println comments[3]](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-12-320.jpg)
![def comments = ['FRIST!', 'YAS!']
println comments[3]](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-14-320.jpg)
![def comments = ['FRIST!', 'YAS!']
println comments[3]
Calls default
methods
i is smaller than
size](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-15-320.jpg)
![def l1 = [1,2,3]
def l2 = []
def l3 = null
println "${l1?.first()}; ${l2?.first()}; ${l3?.first()}"](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-18-320.jpg)
![def l1 = [1,2,3]
def l2 = []
def l3 = null
println "${l1?.first()}; ${l2?.first()}; ${l3?.first()}"](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-20-320.jpg)
![def l1 = [1,2,3]
def l2 = []
def l3 = null
println "${l1?.first()}; ${l2?.first()}; ${l3?.first()}"
Calls different
default method!
Is empty!](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-21-320.jpg)
![String burger = 'burgers'
Long bites = 1
def m = [(burger): [bites]] as Map<String,List<Long>>
println m](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-25-320.jpg)
![String burger = 'burgers'
Long bites = 1
def m = [(burger): [bites]] as Map<String,List<Long>>
println m](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-27-320.jpg)
![def m = [(burger): [bites]] as Map<String,List<Long>>
println m
Evaluated as a bit
shift operation](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-28-320.jpg)
![def m = [(burger): [bites]] as Map<String,List<Long> >
def m = [(burger): [bites]] as Map<String,List<Long>>;](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-29-320.jpg)
![def static hello(n) {
['9': "GR8Conf 2${n}17"]
}
def result = hello 09
println result](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-66-320.jpg)
![def static hello(n) {
['9': "GR8Conf 2${n}17"]
}
def result = hello 09
println result](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-68-320.jpg)
![def static hello(n) {
['9': "GR8Conf 2${n}17"]
}
def result = hello 09
println result
Is it actually an
octal?](https://image.slidesharecdn.com/puzzlers4static-170727183233/85/Groovy-Puzzlers-S04-The-Bytecode-Bites-Back-at-Gr8Conf-US-2017-69-320.jpg)
Groovy Puzzlers S04: The Bytecode Bites Back at Gr8Conf US 2017
- 3. ❤
- 4. ❤ ❤ ❤ ❤ ❤
- 7. Special Danveloper Amendment 1. When Dan get the question right: a.Dan ________ b.Baruch ________ c.The audience ________ 2. When Dan get the question wrong: a.Dan ________ b.Baruch ________ c.The audience ________
- 12. def comments = ['FRIST!', 'YAS!'] println comments[3]
- 14. def comments = ['FRIST!', 'YAS!'] println comments[3]
- 15. def comments = ['FRIST!', 'YAS!'] println comments[3] Calls default methods i is smaller than size
- 18. def l1 = [1,2,3] def l2 = [] def l3 = null println "${l1?.first()}; ${l2?.first()}; ${l3?.first()}"
- 20. def l1 = [1,2,3] def l2 = [] def l3 = null println "${l1?.first()}; ${l2?.first()}; ${l3?.first()}"
- 21. def l1 = [1,2,3] def l2 = [] def l3 = null println "${l1?.first()}; ${l2?.first()}; ${l3?.first()}" Calls different default method! Is empty!
- 25. String burger = 'burgers' Long bites = 1 def m = [(burger): [bites]] as Map<String,List<Long>> println m
- 27. String burger = 'burgers' Long bites = 1 def m = [(burger): [bites]] as Map<String,List<Long>> println m
- 28. def m = [(burger): [bites]] as Map<String,List<Long>> println m Evaluated as a bit shift operation
- 29. def m = [(burger): [bites]] as Map<String,List<Long> > def m = [(burger): [bites]] as Map<String,List<Long>>;
- 32. int burger = 0 int fries = ++burger++ println "Burger: $burger; Fries: $fries"
- 34. int burger = 0 int fries = ++burger++ println "Burger: $burger; Fries: $fries"
- 35. Calls increment with value int burger = 0 int fries = ++burger++ Calls increment with same value
- 38. def thing1 = 0 % 20 def thing2 = 0 % (20 / 1) println thing1 == thing2
- 40. def thing1 = 0 % 20 def thing2 = 0 % (20 / 1) println thing1 == thing2
- 41. Right side is a BigDecimal def thing1 = 0 % 20 def thing2 = 0 % (20 / 1) println thing1 == thing2 Both sides are integers
- 42. def thing2 = 0 % (20 / 1).intValue() def thing2 = 0.toBigDecimal().remainder((20 / 1)).intValue()
- 45. def static theAnswerToLifeTheUniverseAndEverything() { { 42 } } println theAnswerToLifeTheUniverseAndEverything()
- 47. def static theAnswerToLifeTheUniverseAndEverything() { { 42 } } println theAnswerToLifeTheUniverseAndEverything()
- 48. def static theAnswerToLifeTheUniverseAndEverything() { { 42 } } println theAnswerToLifeTheUniverseAndEverything() Ambiguous return statement
- 49. def static theAnswerToLifeTheUniverseAndEverything() { return { 42 } } def static theAnswerToLifeTheUniverseAndEverything() { return { -> 42 } }
- 52. def pathPattern = $/.*/path/to/resource.*/$ Escape rules are different for / def multilinePattern = $/ We can even have multilines. /$
- 56. Confuses the parser println $/.*The Doctor.*/$
- 57. println ($/.*The Doctor.*/$) I HAVE RETURNED!
- 60. doubleVision = { x -> println x } doubleVision("doubleVision${doubleVision}")
- 62. doubleVision = { x -> println x } doubleVision("doubleVision${doubleVision}")
- 63. doubleVision = { x -> println x } doubleVision("doubleVision${doubleVision}")
- 66. def static hello(n) { ['9': "GR8Conf 2${n}17"] } def result = hello 09 println result
- 68. def static hello(n) { ['9': "GR8Conf 2${n}17"] } def result = hello 09 println result
- 69. def static hello(n) { ['9': "GR8Conf 2${n}17"] } def result = hello 09 println result Is it actually an octal?
- 72. def tardis = new Tardis() { static class Tardis { def travel() { "It's Minneapolis in the year 1799!" } } } println tardis.travel()
- 74. def tardis = new Tardis() { static class Tardis { def travel() { "It's Minneapolis in the year 1799!" } } } println tardis.travel()
- 75. Maybe the order of initialization?
- 78. 1. Write readable code 2. Comment your tricks 3. Sometimes it’s only a bug 4. Use static analysis (IntellijIDEA FTW!) 5. RTfM 6.The Parrot will fix it.
- 79. This is the 4th consecutive edition! (Next time in uniform) Puzzlers? Gotchas? Fetal-position inducing behavior? Write to us at: • puzzlers@jfrog.com • @Groovypuzzlers
- 81. Positive feedback? • #groovypuzzlers • @groovypuzzlers • @jbaruch • @danveloper Negative feedback? /dev/null