What is an Expression and What are the types of Expressions?

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.

Example:

a+b
c
s-1/7*f
.
.
etc

Types of Expressions:

Expressions may be of the following types:

  • 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.

Note: An expression may also use combinations of the above expressions. Such expressions are known as compound expressions.



My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.