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Implicit type conversion: Difference between revisions
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=={{header|Java}}==
The Java Language Specification includes several varieties of implicit type conversion. This code illustrates: <ul><li>widening conversions of primitives</li><li>boxing and unboxing conversions</li><li>string conversions (with the + operator)</li></ul>
<lang java>public class ImplicitTypeConversion{
public static void main(String...args){
System.out.println( "Primitive conversions" );
byte by = -1;
short sh = by;
int in = sh;
long lo = in;
System.out.println( "byte value -1 to 3 integral types: " + lo );
float fl = 0.1f;
double db = fl;
System.out.println( "float value 0.1 to double: " + db );
int in2 = -1;
float fl2 = in2;
double db2 = fl2;
System.out.println( "int value -1 to float and double: " + db2 );
int in3 = Integer.MAX_VALUE;
float fl3 = in3;
double db3 = fl3;
System.out.println( "int value " + Integer.MAX_VALUE + " to float and double: " + db3 );
char ch = 'a';
int in4 = ch;
double db4 = in4;
System.out.println( "char value '" + ch + "' to int and double: " + db4 );
System.out.println();
System.out.println( "Boxing and unboxing" );
Integer in5 = -1;
int in6 = in5;
System.out.println( "int value -1 to Integer and int: " + in6 );
Double db5 = 0.1;
double db6 = db5;
System.out.println( "double value 0.1 to Double and double: " + db6 );
}
}
</lang>
{{out}}
<pre>
Primitive conversions
byte value -1 to 3 integral types: -1
float value 0.1 to double: 0.10000000149011612
int value -1 to float and double: -1.0
int value 2147483647 to float and double: 2.147483648E9
char value 'a' to int and double: 97.0
Boxing and unboxing
int value -1 to Integer and int: -1
double value 0.1 to Double and double: 0.1
</pre>
Notice that in the second and fourth conversions the result is a slightly different value.
Not included are:
<ul>
<li>reference conversions (for example, you can treat a reference as if it were a reference to its superclass)</li>
<li>unchecked conversions (the sort of thing that the compiler warns about if you use non-generic collections)
<li>capture conversions (not sure I understand, but it seems to allow wildcard generics where explicit generics would otherise be required)
</ul>
=={{header|jq}}==
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