Sync with the book text: incorporated the latest changes to the examples

Preventing Failure/Check Instructions/Examples/src/QuadraticRequire.kt

@@ -19,8 +19,8 @@ fun quadraticZeroes(
     "Negative underRadical: $underRadical"
   }
   val squareRoot = sqrt(underRadical)
-  val root1 = (-b - squareRoot) / 2 * a
-  val root2 = (-b + squareRoot) / 2 * a
+  val root1 = (-b - squareRoot) / (2 * a)
+  val root2 = (-b + squareRoot) / (2 * a)
   return Roots(root1, root2)
 }
 
@@ -33,7 +33,7 @@ fun main() {
     quadraticZeroes(3.0, 4.0, 5.0)
   } eq "IllegalArgumentException: " +
     "Negative underRadical: -44.0"
-  val roots = quadraticZeroes(3.0, 8.0, 5.0)
-  roots.root1 eq -15.0
-  roots.root2 eq -9.0
+  val roots = quadraticZeroes(1.0, 2.0, -8.0)
+  roots.root1 eq -4.0
+  roots.root2 eq 2.0
 }

Usability/Named & Default Arguments/Examples/src/Evaluation.kt

@@ -2,15 +2,22 @@
 package namedanddefault
 
 class DefaultArg
+val da = DefaultArg()
+
+fun g(d: DefaultArg = da) = println(d)
 
 fun h(d: DefaultArg = DefaultArg()) =
   println(d)
 
 fun main() {
+  g()
+  g()
   h()
   h()
 }
 /* Sample output:
-DefaultArg@28d93b30
-DefaultArg@1b6d3586
+namedanddefault.DefaultArg@7440e464
+namedanddefault.DefaultArg@7440e464
+namedanddefault.DefaultArg@49476842
+namedanddefault.DefaultArg@78308db1
 */

Usability/break & continue/Examples/src/ForControl.kt

@@ -3,10 +3,10 @@ import atomictest.eq
 
 fun main() {
   val nums = mutableListOf(0)
-  for (i in 4 until 100 step 4) { // [1]
-    if (i == 8) continue          // [2]
-    if (i == 40) break            // [3]
+  for (i in 4 until 100 step 4) {    // [1]
+    if (i == 8) continue             // [2]
+    if (i == 40) break               // [3]
     nums.add(i)
-  }                               // [4]
+  }                                  // [4]
   nums eq "[0, 4, 12, 16, 20, 24, 28, 32, 36]"
 }