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enough information to choose which method to call when it encounters sum(1.0,
2.0) in source code.
Reviewing Method-Invocation Rules
The previous examples of method invocation may seem confusing because you can
sometimes specify the method's name directly, whereas you need to prefix a method
voke methods from the various contexts:
• Specifythenameofaclassmethodasisfromanywherewithinthesameclass
as the class method. Example: c2f(37.0);
• Specify the name of the class method's class, followed by the member access
operator, followed by the name of the class method from outside the class.
Example: Conversions.c2f(37.0); (Youcanalsoinvokeaclassmeth-
casual observation the fact that a class method is being invoked.)
• Specify the name of an instance method as is from any instance method,
constructor, or instance initializer in the same class as the instance method.
Example: setName(name);
• Specifyanobjectreference,followedbythememberaccessoperator,followed
by the name of the instance method from any class method or class initializer
within the same class as the instance method, or from outside the class.
Example: Car
Although the latter rule might seem to imply that you can call an instance method
from a class context, this is not the case. Instead, you call the method from an object
Also, don't forget to make sure that the number of arguments passed to a method,
ments agree with their parameter counterparts in the method being invoked.
Note Field access and method call rules are combined in expression Sys-
tem.out.println(); , where the leftmost member access operator accesses the
out class field (of type ) in the java.lang.System
class,andwheretherightmostmemberaccessoperatorcallsthisfield's println()
method. You'll learn about PrintStream in Chapter 8 and System in Chapter 4 .
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