Classes in the same package are implicitly imported into source-code files of other classes in the same package.

Classes System and String are in the package java.lang

An import declaration is not required if you always refer to a class via its fully qualified class name.

We have to use the Java.lang classes by explicitly importing them.

Import declarations involve a package name followed by a dot and the class name.

When classes that are compiled in the same directory on disk are in the same package, this is known as the default package.

Press Enter to submit the string to the program.

Pressing Enter inserts a newline character at the end of the characters the user typed.

Reads individual words.

The newline character is discarded by nextLine.

Reads characters typed by the user until the newline character is encountered.

Return a string containing the characters up to, but not including the new line.

Parentheses in combination with a class name represent a call to a variable, which is similar to a method but is used only at the time an object is created to initialize the object's data.

The keyword new creates a new object of the class specified to the right of the keyword.

Each new class you create becomes a new type.

Parentheses to the right of the class name are required.

It is used to initialize a variable of a class type.

A new type created after a new class can be used to declare variables and create objects. 

Class instance creation is used to initialize a variable of a class type.

Any class can contain a main method since the JVM invokes the main method only in the class used to execute the application.

A call to a constructor is similar to a call to a method but is used only at the time when an object is created to initialize the object's data.

Parentheses in combination with a class name can represent a call to a constructor.

You can call a method that belongs to another class until you create an object of that class.