Type compatibility

As explained in 

Types

, every expression has a type. If an expression is a variable, a constant or a 

parameter, its type is equal to the type of the variable, constant or parameter, of course. This topic 

explains what happens if an expression is composed of two subexpressions with different types.

Consider this example:

3 

+ 

2.1

The type of "3" is int, and the type of "2.1" is float. The type of the resulting expression is always the 

"highest" type of the subexpressions. High means "most descriptive" here. For example, complex is 

higher than float, which is in turn higher than int (boolean expressions are treated differently). So, 

this means the type of the expression above must be float. Since its result should be 5.1, this 

behaves as you would expect.

This means, however, that "3", a constant of type int, must be converted to "3.0", a constant of type 

float. This conversion is performed automatically by the compiler. You should be aware of the fact 

that the compiler can only convert types to higher types. For example, it cannot convert a float to an 

int. So this statement is illegal and results in an error message:

int 

i = 

3.1

Functions like 

round

 and 

real

 are available to perform these conversions manually, if this is 

necessary.

Be aware of the fact that some operators and most functions always return float or complex values. 

For example, this statement is illegal, since the division operator / cannot return an integer result (it 

returns 1.5):

int 

i = 

3 

/ 

2

You can look up the behavior of all 

operators

 and 

functions

 in the Reference section.

The compiler can convert booleans to other types and vice versa, but it does generate a warning for 

each conversion. The value true is converted to 1, and the value false to 0. An expression of 

another type (int, float or complex) is converted to false if it is equal to 0, otherwise it is converted 

to true. Please note that this is only supported for compatibility with old Fractint formulas. It is not 

recommended to use this in new formulas.

Colors cannot be converted automatically. Use the 

rgb

, 

rgba

, 

hsl

, and 

hsla

 functions to convert 

floating point values to colors. Use 

red

, 

green

, 

blue

, 

hue

, 

sat

, 

lum

, and 

alpha

 to convert colors to 

floating point values.

Next: 

Conditionals

See Also

Expressions

Variables

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