JAVA Data Type Ranges - COFPROG

JAVA Data Type Ranges

A Guide to Java's Primitive Data Types

JAVA Data Type Ranges

In Java, primitive data types are the fundamental building blocks for handling data. They represent simple, single values and are stored directly in memory. Understanding their size and range is crucial for writing efficient and error-free code. Let's break them down.

Integer Types

These are used for whole numbers. All integer types in Java are signed, meaning they can hold both positive and negative values.

  • byte
    • Size: 8-bit
    • Range: -128 to 127 ($$-2^7$$to$$2^7 - 1$$)
    • Use: Ideal for saving memory in large arrays where the values are small.
  • short
    • Size: 16-bit
    • Range: -32,768 to 32,767 ($$-2^{15}$$to$$2^{15} - 1$$)
    • Use: Also a good choice for memory saving when a byte is too small.
  • int
    • Size: 32-bit
    • Range: -2,147,483,648 to 2,147,483,647 ($$-2^{31}$$to$$2^{31} - 1$$)
    • Use: The default and most commonly used integer type.
  • long
    • Size: 64-bit
    • Range: -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 ($$-2^{63}$$to$$2^{63} - 1$$)
    • Use: Necessary when you need a range of values larger than an `int` can hold.

Floating-Point Types

These are used for numbers with a fractional part, also known as real numbers. They follow the IEEE 754 standard.

  • float
    • Size: 32-bit (single-precision)
    • Use: Suitable for saving memory in large arrays of floating-point numbers when precision is not the main concern. Be careful with precision loss when converting from large integers.
  • double
    • Size: 64-bit (double-precision)
    • Use: The default choice for decimal values. It offers greater precision than a `float`.

Other Types

  • boolean
    • Size: JVM-dependent, but conceptually represents 1-bit of information.
    • Values: Can only be `true` or `false`. These are language constants.
    • Note: You cannot cast a boolean to any other data type, or vice-versa.
  • char
    • Size: 16-bit
    • Represents: A single Unicode character (UTF-16 code unit).
    • Range: 0 to 65,535
    • Note: Since it's an unsigned type, it can be used for arithmetic operations and can be implicitly converted to an `int`.

Summary Table

Data Type Size Default Value Range / Values
byte 8 bits 0 -128 to 127
short 16 bits 0 -32,768 to 32,767
int 32 bits 0 -2.1 billion to 2.1 billion
long 64 bits 0L -9 quintillion to 9 quintillion
float 32 bits 0.0f Approx. ±3.4e38
double 64 bits 0.0d Approx. ±1.8e308
boolean 1 bit (logical) false true or false
char 16 bits '\u0000' 0 to 65,535





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