An expression is a combination of values, operators, and/or functions that evaluate to a single value. Expressions are used in programming languages to represent computations that produce results. They are a fundamental concept in computer science and programming, and are used in a wide range of contexts, from arithmetic and boolean operations to complex data structures and algorithms.
Expressions can be simple or complex, and can involve different types of data, such as numbers, strings, and boolean values. For example, the following are all examples of expressions:
- 2 + 3
- "Hello" + " world!"
- True or False
- len("hello")
Each of these expressions evaluates to a single value: 5, "Hello world!", True, and 5, respectively.
Expressions can be used in a variety of ways, such as assigning their value to a variable, passing them as arguments to functions, or using them in conditional statements or loops. Understanding expressions is a key component of programming, as they form the basis for many of the computations that a program performs.