Literals (JavaScript and Delphi Prism Cross Reference Guide)

General Info: Programming Literals

A value directly written into the source code of a computer program (as opposed to an identifier like a variable or constant). Literals cannot be changed. Common types of literals include string literals, floating point literals, integer literals, and hexidemal literals. Literal strings are usually either quoted (") or use an apostrophe (') which is often referred to as a single quote. Sometimes quotes are inaccurately referred to as double quotes.

Languages Focus

In addition to understanding whether to use a quote or apostrophe for string literals, you also want to know how to specify and work with other types of literals including floating point literals. Some compilers allow leading and trailing decimals (.1 + .1), while some require a leading or trailing 0 as in (0.1 + 0.1). Also, because floating point literals are difficult for compilers to represent accurately, you need to understand how the compiler handles them and how to use rounding and trimming commands correctly for the nature of the project your are coding.

JavaScript:   quote or apostrophe String literals use either an apostrophe (also known as a single quote) as in 'Prestwood' or quoted as in "Prestwood". If you need to embed an apostrophe in an apostrophe-literal or a quote in a quoted-literal, precede it with a slash as in \' and \". Syntax Example: Alert("Hello"); Alert("Hello \"Mike\".") Alert('Hello'); Alert('Hello Mike\'s website.') //Does JavaScript evaluate this simple //floating point math correctly? No!  if ((.1 + .1 + .1) == .3) {  document.write("Correct") } else {  document.write("Not correct") }  JavaScript Literals (quote or apostrophe)

Delphi Prism:   quote or apostrophe In Prism, you use either quotes or apostrophes for string literals. Different than Delphi, you can start floating point literals with a decimal or an integer. For example, to specify a fractional floating point literal between 1 and -1, you can preceed the decimal with a 0 or not. x := .1 + .1; //Does work. x := 0.1 + 0.1; //Does work. Syntax Example:   MessageBox.Show('Hello'); MessageBox.Show("Hello"); //Example of embedding quotes and apostropes: MessageBox.Show('He said, "Who''s computer?"'); MessageBox.Show("She said, ""Mike's computer"".");