iskm/learnxinyminutes-docs
1
0
Fork 0
mirror of https://github.com/adambard/learnxinyminutes-docs.git synced 2024-12-23 09:41:36 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

- [ADD] PrintWriter example from Java

Browse Source 
- [CHANGE] Extended regex matching with more examples with switch / case
- [CHANGE] String interpolation with formatting and expressions explained.
This commit is contained in:
a.vandijk 2014-08-08 15:19:14 +02:00
parent 0b2f1ff6f1
commit 3cb8d2bcc5
1 changed files with 28 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
scala.html.markdown
View File

@ -299,7 +299,6 @@ Person("George", "1234") == Person("Kate", "1236")
// Pattern matching // Pattern matching
val me = Person("George", "1234") val me = Person("George", "1234")
@ -322,15 +321,22 @@ kate match { case Person("Kate", _) => "Girl"; case Person("George", _) => "Boy"
// Regular expressions // Regular expressions
val email = "(.*)@(.*)".r // Invoking r on String makes it a Regex val email = "(.*)@(.*)".r // Invoking r on String makes it a Regex
val serialKey = """(\d{5})-(\d{5})-(\d{5})-(\d{5})""".r // Using multiline string syntax
val email(user, domain) = "henry@zkpr.com" val matcher = (value: String) => {
println(value match {
"mrbean@pyahoo.com" match { case email(name, domain) => s"It was an email: $name"
case email(name, domain) => "I know your name, " + name case serialKey(p1, p2, p3, p4) => s"Serial key: $p1, $p2, $p3, $p4"
case _ => s"No match on '$value'" // default if no match found
})
} }
matcher("mrbean@pyahoo.com")
matcher("nope..")
matcher("52917")
matcher("52752-16432-22178-47917")
// Strings // Strings
@ -347,17 +353,27 @@ println("ABCDEF".length)
println("ABCDEF".substring(2, 6)) println("ABCDEF".substring(2, 6))
println("ABCDEF".replace("C", "3")) println("ABCDEF".replace("C", "3"))
// String interpolation
val n = 45 val n = 45
println(s"We have $n apples") println(s"We have $n apples")
// Expressions inside interpolated strings are also possible
val a = Array(11, 9, 6) val a = Array(11, 9, 6)
println(s"My second daughter is ${a(2-1)} years old") println(s"My second daughter is ${a(0) - a(2)} years old")
println(s"We have double the amount of ${n / 2.0} in apples.")
println(s"Power of 2: ${math.pow(2, 2)}") // Power of 2: 4.0
// Formatting with interpolated strings (note the prefixed f)
println(f"Power of 5: ${math.pow(5, 2)}%1.0f") // Power of 5: 25
println(f"Square root of 122: ${math.sqrt(122)}%1.4f") // Square root of 122
// Ignoring special characters.
println(raw"New line feed: \n. Carriage return: \r.")
// Some characters need to be 'escaped', e.g. a double quote inside a string: // Some characters need to be 'escaped', e.g. a double quote inside a string:
val a = "They stood outside the \"Rose and Crown\"" val a = "They stood outside the \"Rose and Crown\""
// Triple double-quotes let strings span multiple rows and contain quotes // Triple double-quotes let strings span multiple rows and contain quotes
val html = """<form id="daform"> val html = """<form id="daform">
<p>Press belo', Joe</p> <p>Press belo', Joe</p>
| <input type="submit"> | <input type="submit">
@ -403,7 +419,10 @@ for(line <- Source.fromFile("myfile.txt").getLines())
println(line) println(line)
// To write a file use Java's PrintWriter // To write a file use Java's PrintWriter
val writer = new PrintWriter("myfile.txt")
writer.write("Writing line for line" + util.Properties.lineSeparator)
writer.write("Another line here" + util.Properties.lineSeparator)
writer.close()
``` ```