Expressions
Expressions
An expression can be thought of as as a combination of constants (integer, floating point, and string), functions (built in and user defined), and operators that create a single value when the expression is evaluated.
Numeric Expressions
Numeric expressions in BASIC-256 come in two varieties; 1) integer, and 2) floating point numbers. They are created by using Arithmetic Operators and functions with Numeric Constants and Variables.
Integer Expressions
Integer Expressions are expressions that return a whole number.
Examples include:
| Integer Expressions |
|---|
| 10 |
| ABS(-2345) |
| int(9.987) |
| 5*8 |
Positive integer values may also be expressed in binary (base 2), octal (base 8), and hexadecimal (base 16). Precede binary values with 0b (0b1110 = 14), octal with 0o (0o177 = 127), and hexadecimal with 0x (0xff = 255).
Floating Point Expressions
Expressions that return a decimal number, even if it ends in .0, are known as floating point expressions.
Examples include:
| Floating Point Expressions |
|---|
| 3/7 |
| float(56) |
| sin(2*pi) |
Very large and small floating point numbers may also be represented in scientific E notation (added in version 0.9.9.46). http://en.wikipedia.org/wiki/Scientific_notation
| Scientific E Notation | |
|---|---|
| E Notation | Decimal Number |
| 2e0 | 2 |
| 3e2 | 300 |
| 1.234e10 | 12340000000 |
| -5.3e4 | -53000 |
| 2e-1 | 0.2 |
| 5.12e-9 | 0.00000000512 |
String Expressions
String expressions return text. They are created with the String Operators and the functions that return text, working on String Constants and Variables. See String Expressions.
Boolean Expressions
Boolean expressions answer a true or false question. They are created with the Comparison Operators and the Logical Operators. There is no separate Boolean type: true is the number 1 and false is the number 0. See Boolean Expressions.
Regular Expressions
Regular Expressions are just normal strings but have a specific format used in searching and replacing text.