summaryrefslogtreecommitdiffhomepage
path: root/java.html.markdown
diff options
context:
space:
mode:
authorElijah Karari <eljhkrr@gmail.com>2015-11-02 15:52:27 +0300
committerElijah Karari <eljhkrr@gmail.com>2015-11-02 15:52:27 +0300
commit344518d2f60c6373f7814752fc53ef5603b605a9 (patch)
tree7e48a776ab06c741475b2189527b60a30d291ca8 /java.html.markdown
parentedfc99e198fd2e87802ea81d6779fbadfab64919 (diff)
parent824869ef99de73e87ef791bac880f4575cc9ddc9 (diff)
Merge pull request #2 from adambard/master
Update my fork to upstream
Diffstat (limited to 'java.html.markdown')
-rw-r--r--java.html.markdown25
1 files changed, 16 insertions, 9 deletions
diff --git a/java.html.markdown b/java.html.markdown
index 1813f81c..84978ecc 100644
--- a/java.html.markdown
+++ b/java.html.markdown
@@ -128,7 +128,7 @@ public class LearnJava {
//
// BigInteger can be initialized using an array of bytes or a string.
- BigInteger fooBigInteger = new BigDecimal(fooByteArray);
+ BigInteger fooBigInteger = new BigInteger(fooByteArray);
// BigDecimal - Immutable, arbitrary-precision signed decimal number
@@ -144,7 +144,12 @@ public class LearnJava {
// or by initializing the unscaled value (BigInteger) and scale (int).
BigDecimal fooBigDecimal = new BigDecimal(fooBigInteger, fooInt);
-
+
+ // Be wary of the constructor that takes a float or double as
+ // the inaccuracy of the float/double will be copied in BigDecimal.
+ // Prefer the String constructor when you need an exact value.
+
+ BigDecimal tenCents = new BigDecimal("0.1");
// Strings
@@ -207,8 +212,8 @@ public class LearnJava {
System.out.println("1+2 = " + (i1 + i2)); // => 3
System.out.println("2-1 = " + (i2 - i1)); // => 1
System.out.println("2*1 = " + (i2 * i1)); // => 2
- System.out.println("1/2 = " + (i1 / i2)); // => 0 (0.5 truncated down)
- System.out.println("1/2 = " + (i1 / (i2*1.0))); // => 0.5
+ System.out.println("1/2 = " + (i1 / i2)); // => 0 (int/int returns an int)
+ System.out.println("1/2 = " + (i1 / (double)i2)); // => 0.5
// Modulo
System.out.println("11%3 = "+(11 % 3)); // => 2
@@ -416,7 +421,7 @@ public class LearnJava {
// easier way, by using something that is called Double Brace
// Initialization.
- private static final Set<String> COUNTRIES = HashSet<String>() {{
+ private static final Set<String> COUNTRIES = new HashSet<String>() {{
add("DENMARK");
add("SWEDEN");
add("FINLAND");
@@ -701,10 +706,12 @@ public abstract class Mammal()
// Enum Type
//
-// An enum type is a special data type that enables for a variable to be a set of predefined constants. The // variable must be equal to one of the values that have been predefined for it.
-// Because they are constants, the names of an enum type's fields are in uppercase letters.
-// In the Java programming language, you define an enum type by using the enum keyword. For example, you would
-// specify a days-of-the-week enum type as:
+// An enum type is a special data type that enables for a variable to be a set
+// of predefined constants. The variable must be equal to one of the values that
+// have been predefined for it. Because they are constants, the names of an enum
+// type's fields are in uppercase letters. In the Java programming language, you
+// define an enum type by using the enum keyword. For example, you would specify
+// a days-of-the-week enum type as:
public enum Day {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY,