Introduction to Java

 

Keywords

Java Keywords
abstract continue for new switch
assert default goto package synchronized
break double implements protected throw
byte else import public throws
case enum instanceof return transient
catch extends int short try
char final interface static void
class finally lomg stritfp volatile
const float native super while

Arithmetic Operators

Just like mathematics, Java has several arithmetic operators that you can use for computation. They are:

Java Arithmetic Operators
Operator Meaning Example Outcome
+ Add x, y  = 3,  4
z = x + y		 z is equal to 7
- Subtract x, y = 3, 4
z = x - y;		 z is equal to -1
* Multiply x, y = 3, 4
z = x * y		 z is equal to 12
/ Divide x, y = 6, 2
z = x / y		 z is equal to 3
% Modulus x, y = 5, 3
z = x % y		 z is equal to 2
** Exponent x, y = 2, 3
z = x ** y		 z is equal to 8
// Floor Division x, y = 20, 12
z = x // y		 z is equal to 1

There are a couple of these operators that need some explanation. First the modulus operator will return the remainder for a division problem.

  • 10 % 3 results in 1 be case 10 / 3 = 3 with a remainder of 1
  • 12 % 7 results in 5 Because 12 / 7 = 1 with a remainder of 5

The floor division operator gives a division of a number where the numbers after the decimal point are truncated.

  • 15 // 4 is 3 because 4 goes into 15 three times; the remainder is truncated.

Escape Characters

The following table is a complete list of escape characters that can be used to format strings.

Java Escape Characters
Character Description
 \a  Bell 
 \b  Backspace
 \Cx  Control-x
 \e  Escape
 \f  Formfeed
 \M-\C-x  Meta-Control-x
 \n  Newline
\r  Carriage Return
\s  Space
\t  Tab
\v  Vertical Tab
\x  Character x 
\xnn  Hexadecimal notation. Where n is in the range of 0-9, a-f or A-F

Bitwise Operators

Bitwise operators in Java
Operator Meaning Example
& Bitwise AND x& y = 0 (0000 0000)
| Bitwise OR x | y = 14 (0000 1110)
~ Bitwise NOT ~x = -11 (1111 0101)
^ Bitwise XOR x ^ y = 14 (0000 1110)
>> Bitwise right shift x>> 2 = 2 (0000 0010)
<< Bitwise left shift x<< 2 = 40 (0010 1000)