C++ to java
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The document compares features of C++ and Java during migration from C++ to Java. It discusses features that are not supported in Java like pointers, structures/unions, operator overloading, preprocessor directives, automatic type conversions, global variables/functions, default arguments, and multiple inheritance. It also discusses features gained in Java like threads, packages, interfaces, memory management, API classes, enhanced break/continue, Unicode support, string data type, and documentation comments. Finally, it discusses features that are similar between the languages like booleans, access specifiers, and exception handling. It provides examples of how to address these differences when converting a C++ program to Java.
C++ to java
- 1. Migrating from C++ to Java a path to eternity
- 2. The Differences C++ features not supported by Java Features unique to Java Shared features which differ between C++ and Java
- 3. What Java lacks • Pointers For security reasons • Structures or unions Class is enough • Operator overloading Ambiguity. Causes more troubles than benefit • Preprocessor or preprocessor directive It’s relevance is worth eliminating • Automatic Type conversions Loss of precision
- 4. • Concept of Global Variables/Functions Entire code is encapsulated to classes • Default Arguments Not an ideal approach • Multiple Inheritance Is done using interfaces • Destructors Instead finalize() is used • The << and >> operators Since operator overloading is not supported in Java • Passing objects by value To eliminate ambiguity +the keywords abstract, super, typedef, unsigned int, goto, delete
- 5. What Java Gains • Threads Multithreading allows two or more pieces of the same program to execute concurrently and is supported by Java language itself. • Packages Constructing and using a class library was not this easier yet. • Interfaces Used to implement multiple inheritance. no instance of Interfaces can be created. Similar to Abstract classes in C++. • Sophisticated memory management technique When the last reference to an object is destroyed, the object itself will be deleted on the very next garbage collection.
- 6. • API Classes Substitutes C++ class library.API classes are completely object oriented. • Enhanced break and continue Could accept labels as targets. • Unicode Java character set contains 16-bit wide Unicode characters ensures code portability. • >>> operator Performs unsigned right shift • The documentation comment Delimited using /** and */ • The String data type Helps handle strings in an easy and convenient way +a fully object oriented platform independent programming concept.
- 7. What’s in Common • Boolean In C++ everything except zero will be treated as TRUE, but java won’t! • Access Specifier It’s impossible to assign access specifiers to a group of java variable declarations. • Exception Handling In java, the whole syntax part is similar to C++, but a catch block is mandatory for a thrown exception. Let’s see in what ways these stuff are going to alter the Java counterpart of a previously written C++ program…
- 8. Eliminating Pointers Converting Pointer parameters JC Converting pointers that operate on arrays JC C++ Reference parameters Vs Java Reference param JC Converting C++ Abstract classes into Java Interfaces JC Converting Default Arguments JC Converting C++ Multiple inheritance hierarchies. eg Destructors Vs Finalization JC The Key Aspects
- 9. Ref er ence Java2 Complete Reference http://java.sun.com/ http://www.scs.carleton.ca
- 10. Danks!