Type conversions

Type conversion is a technique in wich variables of different types can be assigned to each other. There are two types of type conversions implicit and explicit. Implicit conversions are handled automatically by the compiler or runtime engine and explicit conversions are handled by the developer.

Basic scalars

The following table describes how the conversion of basic scalars works:

SourceDestinationConversion methodConversion testConversion errorsHow the conversion is done
intint---
intdecimalautomatic--
intdatetime---
intstringautomatic--10 => “10”
intbooleanautomatic--1 => true; value != 0 => false
decimalintint->fromDecimal--Returns the integer part. Any fractional part of this decimal will be discarded. No rounding.
decimaldecimal---
decimaldatetime---
decimalstringstring->fromDecimal--See java documentation for BigDecimal.toString method
decimalbooleanautomatic--1 => true; value != 0 => false
datetimeint---
datetimedecimal---
datetimedatetime---
datetimestringstring->fromDateTime--The date in ISO8601 format.
datetimeboolean---
stringintint->fromStringstring->isIntyes
stringdecimaldecimal->fromStringstring->isDecimalyes
stringdatetimedatetime->fromStringstring->isDateTimeyestrue => if the string is a valid ISO8601 date, false otherwise
stringstring---
stringbooleanbool->fromString--
boolintautomatic--true => 1; false => 0
booldecimalautomatic--true => 1; false => 0
booldatetime---
boolstringautomatic--true => “true”; false => “false”
boolboolean---

Complex scalars

Complex scalars can be implicitly converted by the compiler or runtime engine only if all the properties of the destination type are found in the source type with the same name and type.

The following subchapters present all the possible type convertion situations and the ways you can use type conversions.

Identical structures

The coversion is automatic, properties m1, m2, m3 from source will be set in destination.

classDiagram
    class source {
        m1 as string
        m2 as int
        m3 as boolean
    }

    class destination {
        m1 as string
        m2 as int
        m3 as boolean
    }

Source has more properties

The coversion is automatic, properties m1, m2, m3 from source will be set in destination except for m4 which will be ignored.

classDiagram
    class source {
        m1 as string
        m2 as int
        m3 as boolean
        m4 as decimal
    }

    class destination {
        m1 as string
        m2 as int
        m3 as boolean
    }

Destination has more properties

Conversion must be handled by the developer because destination type has more properties than source type.

classDiagram
    class source {
        m1 as string
        m2 as int
        m3 as boolean
    }

    class destination {
        m1 as string
        m2 as int
        m3 as boolean
        m4 as decimal
    }

Different property names

Conversion must be handled by the developer because destination type has different property names than source type.

classDiagram
    class source {
        m1 as string
        m2 as int
        m3 as boolean
    }

    class destination {
        m4 as string
        m5 as int
        m6 as boolean
    }

Different property types

Conversion must be handled by the developer because destination type has different property types than source type.

classDiagram
    class source {
        m1 as string
        m2 as int
        m3 as boolean
    }

    class destination {
        m1 as boolean
        m2 as string
        m3 as int
    }
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