by Dinesh Thakur Category: Data Type

A computer cannot store characters or integers. Computer can store information in the form of bits and bytes. The bit is a basic unit of information in computer. A bit can only have two values: yes or no, true or false, 1 or 0.



 
by Dinesh Thakur Category: Data Type

The scope of a variable specifies the region of the source program where that variable is known, accessible and can be used. In Java, the declared variable has a definite scope. When a variable is defined within a class, its scope determines whether it can be used only within the defined class or outside of the class also.

 
by Dinesh Thakur Category: Data Type

Java has a wide variety of data types from which we can choose the suitable for a particular purpose. To operate on variables from two different types of data we have to convert Both types to the same.



 
by Dinesh Thakur Category: Data Type

The final modifier indicates that an object is fixed and cannot be changed. When we use this modifier at a class level, it means that the class can never have subclasses. When we apply this modifier to a method, the method can never be overridden. When we apply this modifier to a variable, the value of the variable remains constant. We will get a compile-time error if we try to override a final method or class. We will also get a compile-time error if we try to change the value of a final variable.

 
by Dinesh Thakur Category: Data Type

Static are the members or variables which are defined independently of any object of that class. Static members are the members that can be used by itself, without reference to a specific instance. We can declare both methods and variables to be static. The variables declared as static are global variables. When objects of the class are declared, no copy of a static variable is made. Instead, all instances of the class share the same static variable.

 
by Dinesh Thakur Category: Data Type

Variables are useful when you need to store information that can be changed as program runs. However, there may be certain situations in the program in which the value of variable should not be allowed to modify. This is accomplished using a special type of variable known as final variable. The final variable also called constant variable. It is a variable with a value that cannot be modified during the execution of the program.



 
by Dinesh Thakur Category: Data Type

Type casting is the process of "casting"(Casting mean ‘conversion’ of value to another type) of value to one type to another type of variable.

 
by Dinesh Thakur Category: Data Type

In Volume of a Sphere in Java Example , Math.PI is used because it denotes the value of pi i.e. 3.1414. Math.pow(r,3.0) is used for computing y3

 
by Dinesh Thakur Category: Data Type

Sometimes you have to work with characters that are not listed on the keyboard or with characters that have a special meaning, as symbol as a "newline." They can not be displayed directly in the source the program code, and to use them we need special techniques that will look at now.

 
by Dinesh Thakur Category: Data Type

step 1: Read a character

step 2: Cast it into byte and store in b

step 3: Print b

step 4: Exit

 
by Dinesh Thakur Category: Data Type

When the block is declared without using any modifier, then it is treated as the non-static block is first executed before the constructor is executed. Non-static block directly access the static variable and instance variable.

 
by Dinesh Thakur Category: Data Type

The static modifier is associated only with methods and variables, not classes. The static modifier is used to specify variables that can only be declared once. Static methods are used to specify methods that should not be overridden in subclasses.

 
by Dinesh Thakur Category: Data Type

1. When the variable is declared outside the method, block, and constructor without using any modifier then it is treated as instance variable.
2. If the instance variable is not initialized then it takes the default value of the data type when the object is constructed.
3. Instance variable can use any access specifier.
4. It is accessed within the static method through the object of the class and within the non-static method and constructor directly without creating any object within the class, but outside the class non-static method and constructor invoke instance variable through objects.
5. Instance variable is also known as object level variable as for every instance the value of instance variable is newly initialized.



 
by Dinesh Thakur Category: Data Type
  1. When the variable is declared within the method, block and constructor then the variable is treated as local variable.
  2. Local variable must be initialized before you call it otherwise it generates compile time error.
  3. Same local variable can be declared in two different blocks.
  4. Local variable never use any access specifier. It only takes the default access specifier.
  5. Local variable can never be declared through any access specifier except default access specifier.
 
by Dinesh Thakur Category: Data Type

This Java byte Example shows how to use Java primitive byte variable inside a java class. The byte is a 8 bit signed type ranges from –128 to 127. The syntex For Declare byte varibale is byte <variable name> = <default value>;



 
by Dinesh Thakur Category: Data Type

This Java boolean Variable Example shows how to use Java boolean variable inside a java class. The boolean data type which can have only two values, true or false.



 
by Dinesh Thakur Category: Data Type

This Convert int to string java example shows how to convert int to String in Java.



 
by Dinesh Thakur Category: Data Type

This Swap Numbers Without Using Third Variable Java Example shows how to exchange numbers without using third variable using java. i.e. if the input is n1 100 and n2 200 then after swaping output will be n1 is 200 and n2 is 100. You should not use any temporary variable to swap the numbers.



 
by Dinesh Thakur Category: Data Type

This Swap Numbers Java Example program prints exchange number i.e. if the input is n1 is 100 and n2 is 200 then after swaping output will be n1 is 200 and n2 is 100. You should use any temporary variable to swap the numbers.

 
by Dinesh Thakur Category: Data Type

This Reverse Number using Java program prints reverse number using numeric operations i.e. if the input is 564 then output will be 465. we can see after reversing the integer is print the integer digits in reverse order.

 

Page 1 of 2



About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.