# 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**.

## Recommended Posts:

- Building Expression tree from Prefix Expression
- Difference between fundamental data types and derived data types
- Evaluation of Prefix Expressions
- Check if the given Binary Expressions are valid
- Program to evaluate simple expressions
- Python | Set 2 (Variables, Expressions, Conditions and Functions)
- Find the number of valid parentheses expressions of given length
- Expression Evaluation
- Maximize the value of the given expression
- Maximize the expression (A AND X) * (B AND X) | Bit Manipulation
- Find the minimum value of X for an expression
- Find Range Value of the Expression
- Find all possible outcomes of a given expression
- Arithmetic Expression Evalution
- Expression contains redundant bracket or not

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.