
true and false.
  
'a'), Unicode
  escapes   ('\uxxxx'), and a small set of letter
  escapes ('\t').
  
Name n literal byte8 1short16 -1int32 0long64 0Lor0l
float) or 64-bit
  (double) IEEE-754 floating-point numbers.
  float literals end in f or F; double literals end
  in an optional d or D.
1f,3.14,-0.271e+1D
| 
 
 | 
 
 | 
| target type | |||||||
|---|---|---|---|---|---|---|---|
| byte | char | short | int | long | float | double | |
| byte | |||||||
| char | |||||||
| short | |||||||
| int | |||||||
| long | |||||||
| float | |||||||
| double | |||||||
| : Compatible. | t = s | |
| : Cast required (with possible loss). | t = (t) s | |
| : Compatible with possible loss. | t = s | 


void m() {
  Object o = 42;
  }
void m() {
  Object o = new Integer(42);
  }
primitive-typeValue() in java.lang.Number.
    
void m(String key) {
  if (hashTable.containsKey(key))
    int i = 
      ((Integer) hashTable(key)).intValue();
  }
void m() {
  Object o = 42;
  }
void m(String key) {
  if (hashTable.containsKey(key))
    int i = hashTable(key);
  }
[] access operator. 
    
a referencing an array of elements of type T has
  the declaration
T[] aor Ta[]
T[][] aor Ta[][][]
int [] ia = new int [10];char ttt[][] = new char [3][3];
StringBuffer segs[] = 
  { new StringBuffer(), 
    new StringBuffer(), 
    new StringBuffer() };
char ttt[][] = {
  { ' ', 'x', 'o' },
  { ' ', 'x', 'o' },
  { 'x', 'o', ' ' } };
int p[] = int [] { 2, 3, 5, 7, 11 };
[] initializer is a convenient way to
  construct an anonymous array.
t.sum(int [] { 1, 2, 3 });

point []
getOutliers(double mean, double stdDev) {
  /* blah blah blah */
  }
result = data.getOutliers(m, sd)
if (result != null)
  for (int i = 0; i < result.length; i++)
    // blah blah blah
result = data.getOutliers(m, sd) for (int i = 0; i < result.length; i++) // blah blah blah
[]). 
    
String class has around 70 methods for handling
  strings.
    String methods.
    
char.
  
s1 and s2 are strings, what does s1 == s2 do?
    
s1.equals(s2) do?
    
StringBuilders
    over Strings for manipulating strings.
    
s += "!" for string s.
    
sb.append("!") for string buffer sb.
    
do ??? while not in.eof
s += in.read()1.1 sec sb.apend(in.read())0.17 sec 
toString() MethodString toString()
  returns a printable representation of a class instance.
    Object, not from String. 
    
toString() for significant classes.
employeeName.toString()→
"EmployeeName@1cd2e5f", not so good.
employeeName.toString()→
"George Leroy Tirebiter", better.
toString) and 27 (Return zero-length
  arrays, not nulls) from Effective Java by Joshua Bloch, Addison-Wesley,
  2001.