Operators and Expressions

Operators:

Operators are such symbols that perform some operations on one or more operands. Operators are used to manipulate primitive data types. Once we declare and initialize the variables, we can use operators to perform certain tasks like assigning a value, adding the numbers etc.
Java operators can be classified into different categories as shown:

1. Simple Assignment Operators
2. Arithmetic Operators
3. Unary Operators
4. Equality and Relational Operators
5. Conditional (Logical) Operators
6. Bitwise and Bit Shift Operators

• Java Bitwise AND " &" Operator

• Java bitwise NOT "~" operator

• Java bitwise XOR "^" operator

• Java bitwise OR " |" operator

• Java Left Shift "<<" Operator

• Java Right Shift ">>" Operator

• Java unsigned right shift ">>>"operator 

• Java Truth-Table

   7.   Type Operators

Expressions:

In Java, an expression is like a statement without a terminator ( i.e. statement = expression + ; ). It is  made up of variables, operators, and method invocations, which are defined in accordance to the syntax of the language. The overall coding in a Java program is achieved through the expressions ( which may have single or multiple operations) . In all cases, a single evaluated value is obtained irrespective of composition of the multiple expressions. The evaluation  of an expressions is determined by the order of precedence of the operators.

Few of the examples of expressions are:

int number = 2

arr[0] = 10

int abc = a + (++b)* ((c / a)* b)

System.out.println("Hi,How are you")  // a compound expression

After executing an expression, a value is returned by an expression, it's data type depends on the elements used in the expression
Java also allows you to build the compound expression. 

There are three purposes for defining an expression :

• To compute values.
• To assign values to variables.
• To control the flow of execution.