Sync

Task/Substring/Scala/substring.scala

@@ -1,9 +1,22 @@
-val str = "The good life is one inspired by love and guided by knowledge."
-val n = 21
-val m = 16
+object Substring {
+  // Ruler             1         2         3         4         5         6
+  //         012345678901234567890123456789012345678901234567890123456789012
+  val str = "The good life is one inspired by love and guided by knowledge."
+  val (n, m) = (21, 16) // An one-liner to set n = 21, m = 16
 
-println(str.slice(n, n+m))
-println(str.slice(n, str.length))
-println(str.slice(0, str.length-1))
-println(str.slice(str.indexOf('l'), str.indexOf('l')+m))
-println(str.slice(str.indexOf("good"), str.indexOf("good")+m))
+  // Starting from n characters in and of m length
+  assert("inspired by love" == str.slice(n, n + m))
+  // Starting from n characters in, up to the end of the string
+  assert("inspired by love and guided by knowledge." == str.drop(n))
+  // Whole string minus last character
+  assert("The good life is one inspired by love and guided by knowledge" == str.init)
+  // Starting from a known character within the string and of m length
+  assert("life is one insp" == { val i = str.indexOf('l'); str.slice(i, i + m) })
+  // Alternatively
+  assert("life is one insp" == str.drop(str.indexOf('l')).take(m))
+
+  // Starting from a known substring within the string and of m length
+  assert("good life is one" == { val i = str.indexOf("good"); str.slice(i, i + m) })
+  // Alternatively
+  assert("good life is one" == str.drop(str.indexOf("good")).take(m))
+}