Data types, strings, and the limits of numbers in computers

A data type tells a program what kind of value a variable holds and what can be done with it. Common types include integers (whole numbers), floating-point numbers (numbers with decimals), strings (text), and Booleans (true or false). The type matters: in many languages, 3 + 4 is 7, but "3" + "4" joins two strings into "34." Programs often convert between types, such as turning a typed-in string like "25" into a number. Strings have their own operations, including finding the length, getting a character by its position (often counting from 0), taking a substring, and joining strings together (concatenation). Because computers store numbers in a fixed number of bits, numbers have limits: a value too large for its storage can cause an overflow error, and many decimal values cannot be stored exactly in binary, causing round-off errors, which is why 0.1 + 0.2 produces 0.30000000000000004 in many languages.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report