Expression

  Expression

 An expression is a combination of operators, constants and variables. An expression may consist of one or more operands, and zero or more operators to produce a value.

Type of Expression

 Constant expressions: 

Constant Expressions consists of only constant values. A constant value is one that doesn’t change.

Examples:

5, 10 + 5 / 6.0, 'x’

Integral expressions:

 Integral Expressions are those which produce integer results after implementing all the automatic and explicit type conversions.

Examples:

x, x * y, x + int( 5.0)

where x and y are integer variables.

Floating expressions:

 Float Expressions are which produce floating point results after implementing all the automatic and explicit type conversions.

Examples:

x + y, 10.75

where x and y are floating point variables.

Relational expressions:

 Relational Expressions yield results of type bool which takes a value true or false. When arithmetic expressions are used on either side of a relational operator, they will be evaluated first and then the results compared. Relational expressions are also known as Boolean expressions.

Examples:

x <= y, x + y > 2

Logical expressions:

 Logical Expressions combine two or more relational expressions and produces bool type results.

Examples:

 x > y && x == 10, x == 10 || y == 5 

Pointer expressions: 

Pointer Expressions produce address values.

Examples:

&x, ptr, ptr++

where x is a variable and ptr is a pointer.

Bitwise expressions:

 Bitwise Expressions are used to manipulate data at bit level. They are basically used for testing or shifting bits.

Examples:

x << 3

shifts three bit position to left

y >> 1

shifts one bit position to right.

Shift operators are often used for multiplication and division by powers of two.