C++ vs Java

There are many differences and similarities between the C++ programming language and Java. A list of top differences between C++ and Java are given below:

Comparison Index	C++	Java
Platform-independent	C++ is platform-dependent.	Java is platform-independent.
Mainly used for	C++ is mainly used for system programming.	Java is mainly used for application programming. It is widely used in window, web-based, enterprise and mobile applications.
Design Goal	C++ was designed for systems and applications programming. It was an extension of C programming language.	Java was designed and created as an interpreter for printing systems but later extended as a support network computing. It was designed with a goal of being easy to use and accessible to a broader audience.
Goto	C++ supports the goto statement.	Java doesn't support the goto statement.
Multiple inheritance	C++ supports multiple inheritance.	Java doesn't support multiple inheritance through class. It can be achieved by interfaces in java.
Operator Overloading	C++ supports operator overloading.	Java doesn't support operator overloading.
Pointers	C++ supports pointers. You can write pointer program in C++.	Java supports pointer internally. However, you can't write the pointer program in java. It means java has restricted pointer support in java.
Compiler and Interpreter	C++ uses compiler only. C++ is compiled and run using the compiler which converts source code into machine code so, C++ is platform dependent.	Java uses compiler and interpreter both. Java source code is converted into bytecode at compilation time. The interpreter executes this bytecode at runtime and produces output. Java is interpreted that is why it is platform independent.
Call by Value and Call by reference	C++ supports both call by value and call by reference.	Java supports call by value only. There is no call by reference in java.
Structure and Union	C++ supports structures and unions.	Java doesn't support structures and unions.
Thread Support	C++ doesn't have built-in support for threads. It relies on third-party libraries for thread support.	Java has built-in thread support.
Documentation comment	C++ doesn't support documentation comment.	Java supports documentation comment (/** ... */) to create documentation for java source code.
Virtual Keyword	C++ supports virtual keyword so that we can decide whether or not override a function.	Java has no virtual keyword. We can override all non-static methods by default. In other words, non-static methods are virtual by default.
unsigned right shift >>>	C++ doesn't support >>> operator.	Java supports unsigned right shift >>> operator that fills zero at the top for the negative numbers. For positive numbers, it works same like >> operator.
Inheritance Tree	C++ creates a new inheritance tree always.	Java uses a single inheritance tree always because all classes are the child of Object class in java. The object class is the root of the inheritance tree in java.
Hardware	C++ is nearer to hardware.	Java is not so interactive with hardware.
Object-oriented	C++ is an object-oriented language. However, in C language, single root hierarchy is not possible.	Java is also an object-oriented language. However, everything (except fundamental types) is an object in Java. It is a single root hierarchy as everything gets derived from java.lang.Object.

Note

Java doesn't support default arguments like C++.
Java does not support header files like C++. Java uses the import keyword to include different classes and methods.

C++ Example

File: main.cpp

#include <iostream>
using namespace std;
int main() {
cout << "Hello C++ Programming";
return 0;
}

Java Example

File: Simple.java

class Simple{
public static void main(String args[]){
System.out.println("Hello Java");
}
}

Key Differences Between C++ Vs Java

Now let us discuss some of the key differences between C++ Vs Java, as we proceed in this

tutorial.

#1) Platform Independence

C++ Java

C++ is a platform dependent language.

The source code written in C++ needs to be compiled on every platform. Java is platform-independent.

Once compiled into byte code, it can be executed on any platform.

#2) Compiler and Interpreter

C++ Java

C++ is a compiled language.

The source program written

in C++ is compiled into an object code which can then be executed to produce an output.

Java is a compiled as well as an interpreted language.

The compiled output of a Java source code is a byte code which is platform-independent.

#3) Portability

C++ Java

C++ code is not portable.

It must be compiled for each platform. Java, however, translates the code into byte code.

This byte code is portable and can be executed on any platform.

#4) Memory Management

C++ Java

Memory management in C++ is manual.

We need to allocate/deallocate memory manually using the new/delete operators. In Java the memory management is system-controlled.

#5) Multiple Inheritance

C++ Java

C++ supports various types of inheritances including single and multiple inheritances.

Although there are problems arising from multiple inheritances, C++ uses the virtual keyword to resolve the problems. Java, supports only single inheritance.

Effects of multiple inheritance can be achieved using the interfaces in Java.

#6) Overloading

C++ Java

In C++, methods and operators can be overloaded. This is static polymorphism. In Java, only method overloading is allowed.

It does not allow operator overloading.

#7) Virtual Keyword

C++ Java

As a part of dynamic polymorphism, in C++, the virtual keyword is used with a function to indicate the function that can be overridden in the derived class. This way we can achieve polymorphism. In Java, the virtual keyword is absent. However, in Java, all non-static methods by default can be overridden.

Or in simple terms, all non-static methods in Java are virtual by default.

#8) Pointers

C++ Java

C++ is all about pointers.

As seen in tutorials earlier, C++ has strong support for pointers and we can do a lot of useful programming using pointers. Java has limited support for pointers.

Initially, Java was completely without pointers but later versions started providing limited support for pointers.

We cannot use pointers in Java as leisurely as we can use in C++.

#9) Documentation Comment

C++ Java

C++ has no support for documentation comments. Java has a built-in support for documentation comments (/**…*/). This way Java source files can have their own documentation.

#10) Thread Support

C++ Java

C++ doesn’t have in-built thread support. It mostly relies on third-party threading libraries. Java is in-built thread support with a class “thread”. We can inherit the thread class and then override the run method.

Some more differences…

#11) Root Hierarchy

C++ is procedural as well as an object-oriented programming language. Hence it does not follow any specific root hierarchy.

Java is a pure object-oriented programming language and has a single root hierarchy.

#12) Source Code & Class Relationship

In C++, both the source code and filename do not have any relationship. This means that we can have many classes in the C++ program and the filename can be anything. It need not be the same as the class names.

In Java, there is a close relationship between the source code class and the filename. The class containing the source code and the filename should be the same.

For Example, if we have a class in Java named salary, then the filename which contains this class code should be “salary.java”.

#13) Concept

The concept behind C++ programs is written once and compile anywhere as C++ is not platform-independent.

On the contrary, for Java programs it is written once, run everywhere and anywhere as the byte code generated by Java compiler is platform-independent and can run on any machine.

#14) Compatibility With Other Languages

C++ is built upon C. C++ language is compatible with most of the other high-level languages.

Java is not compatible with other languages. As Java was inspired by C and C++, its syntax is similar to these languages.

#15) Type Of Programming Language

C++ is both a procedural and object-oriented programing language. Hence, C++ has features specific to procedural languages as well as features of object-oriented programming language.

Java is a completely object-oriented programming language.

#16) Library Interface

C++ allows direct calls to the native system libraries. Hence it is more suited for system-level programming.

Java has no direct call support to its native libraries. We can call the libraries through Java Native Interface or Java Native Access.

#17) Distinguishing Features

Features related to the procedural languages and object-oriented language are the distinguishing features of C++.

Automatic garbage collection is the distinguishing feature of Java. Meanwhile, Java does not support destructors.

#18) Type Semantics

As far as type semantics for C++ are concerned, primitive and object types are consistent.

But for Java, there is no consistency between the primitive and object types.

#19) Input Mechanism

C++ uses cin and cout along with ‘>>’ and ‘<<’ operators respectively to read in and write the data.

In java, the System class is used for input-output. To read the input, System.in which reads one byte at a time is used. The construct System.out is used to write the output.

#20) Access Control And Object Protection

C++ has a flexible model for objects with access specifiers controlling the access and strong encapsulation ensuring protection.

Java has a comparatively cumbersome object model with weak encapsulation.

#21) Goto Statement

C++ supports the goto statement, but its use should be minimized in order to prevent the consequences of using it in a program.

Java does not provide support for the goto statement.

#22) Scope Resolution Operator

Scope resolution operator is used to access the global variables and define methods outside the class.

C++ supports scope resolution operator as it uses it to access global variables. It also allows us to define functions outside the class and access them using the scope resolution operator.

In contrast, Java doesn’t support the scope resolution operator. Java also doesn’t allow defining the functions outside. Everything related to the program including the main function needs to be inside a class.

#23) Try/Catch Block

In C++, we can exclude the try/catch block even if we know that the code might throw an exception.

However, in Java, if we are sure that the code will throw an exception, then we must include this code under the try/catch block. Exceptions are different in Java as it doesn’t support destructors.

#24) Runtime Error Detection

In C++ the runtime error detection is the programmer’s responsibility.

In Java, the runtime error detection is controlled by the system.

#25) Language Support

Because of its proximity to hardware, and libraries that allow accessing system resources, C++ is more suitable for system programming although we have a wide range of applications including database, enterprise, gaming, etc. developed in C++.

#26) Data And Functions

C++ has a global scope as well as namespace scope. Thus data and functions can exist outside the class as well.

In Java, all data and functions need to be in the class. There is no global scope, however, there can be package scope.

#27) Structures & Unions

Structures and Unions are data structures that can have members with different data types. C++ supports both structures and unions.

Java, however, does not support structures or unions.

#28) Object Management

In C++ objects are managed manually. The creation and destruction of objects are carried out manually using the new and delete operators respectively. We also use constructors and destructors for class objects.

Java does not support destructors though it supports constructors. Java is also heavily dependent on automatic garbage collection for collecting and destroying objects.

#29) Parameter Passing

Pass by Value and pass by reference are the two important parameter passing techniques used in programming. C++ supports both these techniques.

However, Java supports only pass by Value technique of parameter passing.

#30) Hardware

C++ is close to hardware and has many libraries that can manipulate the hardware resources. Because of its closeness to hardware, C++ is often used for system programming, gaming applications, operating system, and compilers.

Java is mostly an application development language and is not close to the hardware.

Frequently Asked Questions In C++ And Java

Q #1) Which one is better C++ or Java?

Answer: Well, we cannot definitely say which is better. Both C++ and Java have their own merits and demerits. While C++ is mostly good for system programming, we cannot do it with Java. But Java excels in applications like web, desktop, etc.

In fact, C++ can do anything from system programming to enterprise to gaming. Java can do more of a web or enterprise. There are some applications like certain low-level programming applications or gaming etc. which cannot be left for Java to develop.

Thus it totally depends on what application we are developing. The best way is to evaluate beforehand the pros and cons of both the languages and verify their uniqueness for the application that we are developing and then conclude which is the best.

Q #2) Is C++ more powerful than Java?

Answer: Again this is a tricky question! When it comes to how easier is the syntax or learning the language, Java scores. When it comes to system programming and/or other low-level applications, C++ is more powerful.

Some people might argue that having automatic GC collections, no pointers, no multiple inheritances make Java more powerful.

But when it comes to speed, C++ is powerful. Also in applications like gaming where we need to store the state, automatic garbage collection can ruin the tasks. Thus C++ is obviously powerful here.

Q #3) Can we learn Java without knowing C or C++?

Answer: Yes, definitely!

Once we know the fundamentals of programming and object-oriented programming concepts, we can begin learning Java.

Q #4) Is C++ like Java?

Answer: In some ways, Yes but in some ways, No.

Like for example, both C++ and Java are object-oriented programming languages. They can be used for application development. They have similar syntax.

But in other cases like memory management, inheritance, polymorphism, etc., C++ and Java are completely different. Similarly, when it comes to primitive data types, object handling, pointers, etc. both the languages are different.

Q #5) Is Java written in C++?

Answer: Java in the sense the Java Virtual Machine (JVM) by Sun and IBM are written in C++. The Java libraries are in Java. Some other JVMs are written in C.

Conclusion

C++ and Java are both object-oriented programming languages. In addition, C++ is a procedural language as well. There are some features like inheritance, polymorphism, pointers, memory management, etc. in which both the languages completely differ with one another.

There are some characteristics of C++ like closeness to hardware, better object management, speed, performance, etc. which makes it more powerful than Java and thus motivate the developers to use C++ for low-level programming, high-speed gaming applications, system programming, etc.

In a similar way, the easier syntax of Java, automatic garbage collection, lack of pointers, templates, etc. make Java a favorite for web-based applications.