![]() For details about the search strategy, see How Classes Are Found at Ĭlass libraries for most applications use the extensions mechanism. The JDK, the JVM and other JDK tools find classes by searching the Java platform (bootstrap) classes, any extension classes, and the class path, in that order. The default is the current directory to conveniently enable those classes to be found. The class path needs to find any classes you have compiled with the javac compiler. The class path tells the JDK tools and applications where to find third-party and user-defined classes that are not extensions or part of the Java platform. ) in the new settings.Ĭlass path entries that are neither directories nor archives (.zip or JAR files) nor the asterisk ( *) wildcard character are ignored. Setting the CLASSPATH variable or using the -classpath command-line option overrides that default, so if you want to include the current directory in the search path, then you must include a dot (. The default class path is the current directory. Multiple path entries are separated by semicolons with no spaces around the equals sign (=) in Windows and colons in Oracle Solaris. Each class path should end with a file name or directory depending on what you are setting the class path to, as follows:įor a JAR or zip file that contains class files, the class path ends with the name of the zip or JAR file.įor class files in an unnamed package, the class path ends with the directory that contains the class files.įor class files in a named package, the class path ends with the directory that contains the root package, which is the first package in the full package name. For a listing, see JDK Tools and Utilities at classpath1:classpath2Ĭlass paths to the JAR, zip or class files. sdkToolĪ command-line tool, such as java, javac, javadoc, or apt. SdkTool -classpath classpath1 classpath2. The -classpath option is preferred because you can set it individually for each application without affecting other applications and without other applications modifying its value. Thus, the data drawing class might declare four methods named draw, each of which has a different parameter list.The class search path (class path) can be set using either the -classpath option when calling a JDK tool (the preferred method) or by setting the CLASSPATH environment variable. In the Java programming language, you can use the same name for all the drawing methods but pass a different argument list to each method. It is cumbersome to use a new name for each methodfor example, drawString, drawInteger, drawFloat, and so on. Suppose that you have a class that can use calligraphy to draw various types of data (strings, integers, and so on) and that contains a method for drawing each data type. This means that methods within a class can have the same name if they have different parameter lists (there are some qualifications to this that will be discussed in ![]() The Java programming language supports overloading methods, and Java can distinguish between methods with different method signatures. However, a method might have the same name as other methods due to method overloading. Typically, a method has a unique name within its class. ![]() Modifiers, return types, and parameters will be discussed later in this The method body, enclosed between bracesthe method's code, including the declaration of local variables, goes here. ![]() An exception listto be discussed later.If there are no parameters, you must use empty parentheses. The parameter list in parenthesisa comma-delimited list of input parameters, preceded by their data types, enclosed by parentheses, ().The method namethe rules for field names apply to method names as well, but the convention is a little different.The return typethe data type of the value returned by the method, or void if the method does not return a value.Modifierssuch as public, private, and others you will learn about later.More generally, method declarations have six components, in order: The only required elements of a method declaration are the method's return type, name, a pair of parentheses, (), and a body between braces. Public double calculateAnswer(double wingSpan, int numberOfEngines,
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