Java Programming

The important keywords used in Java with respect to Exception Handling are:

a. Throw - The "throw" keyword is used to throw exceptions from inside a method

b. Throws - The "throws" keyword is used to signify the fact that the code contents within the current method may be throwing an exception and the calling method must handle them appropriately

#include<stdio.h>

bool is_prime (unsigned n) {

if (n<2) return false;

if (!(n%2)) return n==2;

unsigned max_factor = (unsigned) sqrt (n) + 1;

unsigned factor;

for (factor=3; factor<max_factor; ++factor) {

if (!(n%factor)) return false;

}

return true;

}

unsigned next_prime (unsigned n) {

while (!is_prime (++n));

return n;

}

int main() {

/* print the first 100 prime numbers */

unsigned i, n=0;

for (i=0; i<100; ++i) {

n = next_prime (n);

printf ("%d\n", n);

}

return 0;

}

1. A Vector is a collection while an Array is a simple data type
2. Vectors are thread safe by default, arrays are not
3. Vectors can grow in size automatically whereas you have to declare the initial size of an array and it does not grow in size

final int limit = 1000000;

// Print evens...

for(int i = 0; i <= limit; i += 2) {

System.out.print(i + " ");

}

// Print odds...

for(int i = 1; i <= limit; i += 2) {

System.out.print(i + " ");

}

PHP is a scripting language mostly used for web development. It is dynamically typed - variable type can change at runtime. You can use procedural or object-oriented approach in PHP and recent versions are adding elements of functional programming too (closures and yielding, for example.) There is no method overloading, but methods and functions can have optional parameters.

Java is strictly object-oriented, compiled to bytecode, and uses strong (statical) typing. Methods can be overloaded by declaring them with different argument types.

There are many differences in syntax as well, and the way environments for development and production are setup and maintained.

Java applets

Static:

we can use the keyword static either to method or to a variable.

when we declare to a method,(eg: public static void main(String args[]),we can use this method without any object.

when we use to a variable,there will be only one instance of that variable irrespective of how many objects that get created of that class.

Final:

Usage of final to method or to a variable makes them as constant. It's value cannot be changed...

A constructor creates an Object of the class that it is in by initializing all the instance variables and creating a place in memory to hold the Object. It is always used with the keyword new and then the Class name. For instance, new String(); constructs a new String object. Sometimes in a few classes you may have to initialize a few of the variables to values apart from their predefined data type specific values. If java initializes variables it would default them to their variable type specific values. For example you may want to initialize an integer variable to 10 or 20 based on a certain condition, when your class is created. In such a case you cannot hard code the value during variable declaration. such kind of code can be placed inside the constructor so that the initialization would happen when the class is instantiated.

in a way but yea i would not recomend it, it slows down your PC.

It depends on what you mean by "convert an int to char".

If you simply want to cast the value in the int, you can cast it using Java's typecast notation:

int i = 97; // 97 is 'a' in ASCII

char c = (char) i; // c is now 'a'

If you mean transforming the integer 1 into the character '1', you can do it like this:

if (i >= 0 && i <= 9) {

char c = Character.forDigit(i, 10);

....

}

A data type is, well, the type of data. The most common types are strings (text with spaces, punctuation, etc), integers (whole numbers within a certain range, depending on the specific type), and decimal numbers (1.7). Depending on the database software, there will be many other types.

false sealed classes cannot be inherited

No. A String is handled as an Object. In many cases you can treat it as primitive (and forget that it is an object), but sometimes the difference is relevant. The class is called String - note that it starts with an uppercase "S".

One case where it is important to know that a String is an object is when comparing strings. You can't simply use the ==operator; instead, you have to use the .equals()method.

No. A String is handled as an Object. In many cases you can treat it as primitive (and forget that it is an object), but sometimes the difference is relevant. The class is called String - note that it starts with an uppercase "S".

One case where it is important to know that a String is an object is when comparing strings. You can't simply use the ==operator; instead, you have to use the .equals()method.

No. A String is handled as an Object. In many cases you can treat it as primitive (and forget that it is an object), but sometimes the difference is relevant. The class is called String - note that it starts with an uppercase "S".

One case where it is important to know that a String is an object is when comparing strings. You can't simply use the ==operator; instead, you have to use the .equals()method.

No. A String is handled as an Object. In many cases you can treat it as primitive (and forget that it is an object), but sometimes the difference is relevant. The class is called String - note that it starts with an uppercase "S".

One case where it is important to know that a String is an object is when comparing strings. You can't simply use the ==operator; instead, you have to use the .equals() method.

The only disadvantage of operator overloading is when it is used non-intuitively. All operators must behave with predictable results, thus it makes no sense to implement the plus (+) operator so that it behaves like a subtract (-) operator, or a multiply (*) operator, or indeed anything other than the intuitive sum of two objects.

Generics are a part of generic programming within Java. They are commonly used to hold objects of any type, within a Java Collection Framework (JCF), and are a reusable data collection tool.

Enum in java is a keyword which is introduced in JDK 1.5 and its a type like Interface and Class.Enum constants are implicitly static and final and you can not change there value once created. Enum in Java provides type-safety and can be used inside switch statment like int variables. Since enum is a keyword you can not use as variable name and since its only introduced in JDK 1.5 all your previous code which has enum as variable name will not work and needs to be refactored.

you can play the jar files by transfer it in to nokia mobile phones

Polymorphism is Greek for "many forms". There are two types of polymorphism: static and dynamic. Static polymorphism occurs at compile time and is also known as compile time polymorphism. Dynamic polymorphism occurs at runtime and is also known as runtime polymorphism.

Runtime polymorphism is a primary feature of the object-oriented programming paradigm. We achieve runtime polymorphic behaviour by defining virtual methods in a base class which derived classes can then override in order to provide more specialised implementations. Whenever we invoke one of these methods, the most-specialised override is executed automatically. In other words, polymorphic objects will behave according to their runtime type even when the runtime type cannot be determined at compile time.

An object is an _instance_ of a class. A good example is to think of a class as a blueprint for a house, whereas an object is the actual house. You can have many, many houses (objects) build from the same blueprint (class)

Classes and packages together help us organize our programs. They help us split logically related functionality or pieces of code into separate classes and packages thereby helping us in maintaining them in future. for ex: I will put all the class related to the user login functionality inside one package and so in future if I have to make any changes to that feature, I can simply go to that package and do what I want.

12345

1234

123

12

1

<script type = "text/javascript">

var input;

var rev = 0;

input=window.prompt ("Please enter a 5-digit number to be reversed.");

input = input * 1;

while (input > 0)

{

rev *= 10;

rev += input % 10;

input /= 10;

}

document.write ("Reversed number: " + rev);

</script>