- The Java programming language defines eight primitive data types.
-boolean (for logical)
-char (for textual)
-byte
-short
-int
-long (integral)
-double
-float (floating point).
Logical-boolean
- A boolean data type represents two states: true and false.
- An example is, boolean result = true;
- The example shown above, declares a variable named result as boolean type and assigns it a value of true.
Textual-char
- A character data type (char), represents a single Unicode character.
- It must have its literal enclosed in single quotes(’ ’).
- For example: ‘a’ //The letter a ‘\t’ //A tab
- To represent special characters like ' (single quotes) or " (double quotes), use the escape character '\'.
- For example, '\'' //for single quotes '\"' //for double quotes
- Although, String is not a primitive data type (it is a Class), we will just introduce String in this section.
- A String represents a data type that contains multiple characters. It is not a primitive data type, it is a class.
- It has its literal enclosed in double quotes(“”).
- For example: String message=“Hello world!”;
Integral – byte, short, int & long
- Integral data types in Java uses three forms – decimal, octal or hexadecimal.
- Examples are, 2 //The decimal value 2 077 //The leading 0 indicates an octal value 0xBACC //The leading 0x indicates a hex value
- Integral types has int as default data type.
- You can define its long value by appending the letter l or L.
- For example:10L
Floating Point – float and double
- Floating point types has double as default data type.
- Floating-point literal includes either a decimal point or one of the following, E or e //(add exponential value) F or f //(float) D or d //(double)
- Examples are:
3.14 //A simple floating-point value (a double)
6.02E23 //A large floating-point value
2.718F //A simple float size value
123.4E+306D//A large double value with redundant D
