What does the author try to tell us about the toString() method in this excerpt:
The
toString()method of theIntegerclass is automatically used when a string of characters is needed in the next to last statement. ThetoString()method of theDoubleclass is automatically used when a string of characters is needed last statement.
when discussing this code:
Integer value = new Integer(103);
Double dvalue = new Double(-32.78);
System.out.println( "Integer object holds: " + value );
System.out.println( "Double object holds: " + dvalue );
The toString() method of the Integer class is automatically used when a string of characters is needed in the next to last statement.
There is code accompanying the text you quoted. The next to last statement in the code is:
System.out.println( "Integer object holds: " + value );
where value is an instance of Integer.
To perform the concatenation "Integer object holds: " + value, the value must be converted to a string. The toString() method of Integer is invoked to perform this conversion.
Similarly the statement:
System.out.println( "Double object holds: " + dvalue );
involves invoking the toString() method of Double to convert dvalue to a string.