Literals

Literals
An Introduction with Examples in Java

Prof. David Bernstein
James Madison University

Computer Science Department

bernstdh@jmu.edu

Review

Literals

Some Literals in Java

Numeric Literals

Grouping Character:
- You can't use a comma (US-style) or dot (European-style) as a grouping character (e.g., 100,000 is not a valid int literal) but you can use an underscore (e.g., 100_100 is a valid int literal)
Integer vs. Floating Point:
- A numeric literal without a dot is always an integer number
- A numeric literal with a single dot is always a floating point number even if there are no digits to the right (e.g., 1. is a double literal)

Character Literals

Most Character Literals:
- Consist of a single symbol enclosed in single quotes (e.g., 'a', '7', '[')
A Consequence:
- The single quote literal must be represented in a special way, using what is called an escape sequence, which, in many languages, is a symbol preceded by a backslash (e.g., '\'')
A Cascading Consequence:
- The backslash literal must also be escaped (i.e., '\\')
Other Escaped Character Literals:
- '\t' is the tab literal
- '\n' is the newline literal
- '\r' is the carriage return literal
- '\"' is the double quote literal (the need for which will become apparent later)

Java vs. Python - Important Differences

Characters:
- In Python, there is no equivalent to char (a string of a single character is used instead)
Quotes:
- In Python, both single quotes and double quotes can be used in string literals whereas in Java single quotes are used for char literals and double quotes are used for String literals
Backslash:
- In Python, the backslash (not in a string) is used as the line continuation character
Boolean Literals:
- In Python, True and False are used (instead of true and false)