Which of these is not a character?

In the context of programming and data types, a character typically refers to a single letter, digit, or symbol that is represented within single quotes. The correct answer identifies '3.0' as not being a character because it is a decimal number represented as a string, comprising two digits and a decimal point.

Characters are individual units such as letters, numbers, and symbols that are recognized by the programming language. For instance, 'a', '%', and '$' are all individual characters that can be processed independently. In contrast, '3.0' implies a numeric representation with more than one character (the digit '3', the decimal point, and the digit '0'), which does not fall under the definition of a single character.

Understanding this distinction is crucial when manipulating strings and data types in programming, as treating '3.0' as a character would not yield the expected behavior within data structures or algorithms where individual characters are required.