What does the word "literal" mean?

Question

What does the word "literal" mean when used in context such as literal strings and literal values? What is the difference between a literal value and a value?

Answer 1

Consider the assignment statement:

Y = 3x + 2

This is the slope-intercept form of the equation of a line. The current value of the variable x (note: programming languages may or may not generate code that retrieves this value before a value has been set). That value is multiplied by 3 (a literal; always 3), then 2 (another literal) is added and the total is stored in the variable Y (replacing the previous value stored in Y).

Note that a Von Neumann architecture computer stores both program and data in the same memory. If, either by accident or by clever programming, the value stored in the literal 3 in memory becomes 4, the computer uses the 4 although the program initially said it should be 3.

So, the distinction is not between a literal value and a value; it is between a literal and a variable. They are identified differently in the Symbol Table when the program is compiled or interpreted.