Data types

Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in the memory.

Based on the data type of a variable, the operating system allocates memory and decides what can be stored in the reserved memory. Therefore, by assigning different data types to variables, you can store integers, decimals, or characters in these variables.

Data types :

Byte Short Int Long Float Double Boolean Char A. Byte Byte data type is a 8-bit signed two's complement integer Minimum value is : -128 (-2^7) Maximum value is : 127 (inclusive)(2^7 -1) Default value is : 0 Byte data type is used to save space in large arrays, mainly in place of integers, since a byte is four times smaller than an int Syntax : byte Variable_Name = Value; Example (DataType_Byte.java) : public class DataType_Byte { public static void main(String[] args) { // TODO Auto-generated method stub byte a = 50; byte b = (byte) -80;         byte c = (byte) (a + b);     System.out.println("The Byte Value is : " + c);   } } Sample Output The Byte Value is : -30 B. Short Short data type is a 16-bit signed two's complement integer Minimum value is : -32,768 (-2^15) Maximum value is : 32,767(inclusive) (2^15 -1) Default value is : 0 Short data type can also be used to save memory as byte data type. A short is 2 times smaller than an int Syntax : short Variable_Name = Value; Example (DataType_Short.java) : public class ShortType { public static void main(String[] args) { // TODO Auto-generated method stub short a = 1000; short b = -1500;       short c = (short) (a+b);     System.out.println("The Short Value is : " + c);   } } Sample Output The Short Value is : -500 C. Int Int data type is a 32-bit signed two's complement integer Minimum value is : -2,147,483,648.(-2^31) Maximum value is : 2,147,483,647(inclusive).(2^31 -1) Default value is : 0 Int is generally used as the default data type for integral values unless there is a concern about memory Syntax : int Variable_Name = Value; Example (DataType_Int.java) : public class DataType_Int { public static void main(String[] args) { // TODO Auto-generated method stub int a = 15000; int b = 20000;   int c = a + b; System.out.println("The int Value is : " + c);     } } Sample Output The int Value is : 35000 D. Long Long data type is a 64-bit signed two's complement integer Minimum value is : -9,223,372,036,854,775,808.(-2^63) Maximum value is : 9,223,372,036,854,775,807 (inclusive). (2^63 -1) Default value is : 0L This type is used when a wider range than int is needed Syntax : long Variable_Name = Value_L; Example (DataType_Long.java) : public static void main(String[] args) { // TODO Auto-generated method stub int lightspeed;  long days;  long seconds;  long distance;  // approximate speed of light in miles per second  lightspeed = 186000;  days = 1000; // specify number of days here  seconds = days * 24 * 60 * 60; // convert to seconds  distance = lightspeed * seconds; // compute distance  System.out.print("In " + days);  System.out.print(" days light will travel about ");  System.out.println(distance + " miles.");    } } Sample Output In 1000 days light will travel about 16070400000000 miles. E. Float Float data type is a single-precision 32-bit IEEE 754 floating point Default value is : 0.0f Float data type is never used for precise values such as currency Float is mainly used to save memory in large arrays of floating point numbers Syntax : float Variable_Name = (float) Value; Example (DataType_Float.java) : public class DataType_Float { float a = 10.56f; float b = 23.57f;   float c = a + b; System.out.println("The Float Vaue is : " + c); } } Sample Output The Float Vaue is : 34.13 F. Double double data type is a double-precision 64-bit IEEE 754 floating point Default value is : 0.0d Double data type should never be used for precise values such as currency This data type is generally used as the default data type for decimal values. generally the default choice Syntax : double Variable_Name = Value; Example (DataType_Double.java) : public class DoubleType { public static void main(String[] args) { // TODO Auto-generated method stub double a = 123.456; double b = 45.894;   double c = a + b; System.out.println("The Double Value is : " + c);   double d = a - b; System.out.println("The Double Value is : " + d);   } } Sample Output The Double Value is : 169.35 The Double Value is : 77.56200000000001 G. Boolean boolean data type represents one bit of information There are only two possible values : true and false This data type is used for simple flags that track true/false conditions Default value is : false Syntax : boolean Variable_Name = Value (true/false); Example (DataType_Boolean.java) : public class DataType_Boolean { boolean a = true; if(a == true) { a = false; System.out.println("The Boolean Value is : " + a); } } } Sample Output The Boolean Value is : false H. Char char data type is a single 16-bit Unicode character Minimum value is : '\u0000' (or 0) Maximum value is : '\uffff' (or 65,535 inclusive) Char data type is used to store any character Syntax : char Variable_Name = Value; Example (DataType_Char.java) : public class Chartype { public static void main(String[] args) { // TODO Auto-generated method stub char a = 'J'; char b = 'A'; char c = 'V'; char d = 'A';   System.out.println("The Characters Value is : " + a+b+c+d); } } Sample Output The Characters Value is : JAVA