Expression
An expression is a combination of values, variables, and operators that produces a result. An expression always evaluates to a single value.
Why expressions are important
Expressions are used to:
Perform calculations
- Compare values
- Create logical conditions
- Generate results inside programs
Most lines of code contain expressions.
Simple examples
Arithmetic expression:
Result → 8
Using variables:
If price = 10 and quantity = 2, the expression evaluates to 20.
Boolean expression
An expression can also return true or false.
Example:
This expression evaluates to:
trueif age is 18 or morefalseotherwise
Boolean expressions are often used in conditions.
Expression vs Statement
- Expression → produces a value
- Statement → performs an action
Example:
The expression creates the value.
The statement uses it.
Expressions inside functions
Expressions are often used with return values.
Example:
Here, a + b is the expression.
Why learning expressions matters
Understanding expressions helps you:
- Build calculations
- Write conditions
- Create dynamic logic
- Understand how code produces results
Expressions are the core building blocks of programming.
Simple example
Think of an expression like a math formula. You combine numbers and symbols, and you get a result.
Related terms
- What is Parameter?
- What is Return Value?
- What is Scope?
Source
Simplified from general programming documentation and Wikipedia.