How many numbers does java int have?

In Java, int is a 32-bit signed data type, and its variables require 32-bit memory; the valid range of the int data type is -2147483648 to 2147483647, and all integers in this range are called integer literals. An integer literal can be assigned to an int variable, such as "int num1 = 21;".

The operating environment of this tutorial: windows7 system, java8 version, DELL G3 computer.

Java int data type

The int data type is a 32-bit signed Java primitive data type.

Variables of int data type require 32-bit memory.

The valid range is -2,147,483,648 to 2,147,483,647 (-231 to 231 - 1).

• For a positive number, its complement is itself.

• For a negative number, its complement is the inversion of all the bits of the binary number of the corresponding positive number plus one.

• The same operation is used to find the original code from the complement of a negative number (all bits are inverted by 1), which is the absolute value of the negative number

All integers in this range are called integer literals.

For example, 10, -200, 0, 30, 19, etc. are the integer literal values ​​of int.

An integer literal can be assigned to an int variable, such as num1, like this:

int num1 = 21;

Integer literal

Integer literal can also be used Represents

• Decimal number format

• Octal number format

• Hexadecimal number format

• Binary number format

When an integer literal starts with zero and has at least two digits, it is considered to be in octal number format.

The following lines of code assign the decimal value 17 (021 in octal) to num1:

// 021  is in octal number format, not  in  decimal 
int num1 = 021;

The following two lines of code have the same effect of assigning the value 17 to the variable num1:

The following values ​​do not have leading zeros and are in decimal number format.

int num1 = 17;

The following value has leading zeros, so it is in an octal number format. 021 in octal is the same as 17 in decimal.

int num1 = 021;

An int literal in octal format must have at least two digits and must start with zero to be treated as an octal number.

The number 0 is treated as zero in decimal number format, and 00 is treated as zero in octal number format.

All int literals in hexadecimal number format begin with 0x or 0X, and they must contain at least one hexadecimal digit.

The hexadecimal number format uses 16 digits, 0-9 and A-F (or a-f).

The letters A to F are irrelevant.

The following is an example of using an int literal in hexadecimal format:

int num1 = 0x123;
int num2 = 0xdecafe; 
int num3 = 0x1A2B; 
int num4 = 0X0123;

You can use binary number format to represent an int literal.

All int literals in binary number format begin with 0b or 0B.

The following is an example of using an int literal in binary number format:

int num1 = 0b10101; 
int num2 = 0b00011; 
int num3 = 0b10;
int num4 = 0b00000010;

Java has a class called Integer, which defines two constants to represent the maximum and minimum values ​​of the int data type values, namely Integer.MAX_VALUE and Integer.MIN_VALUE. For example,

int max = Integer.MAX_VALUE;  // Assigns maximum  int  value to max 
int min = Integer.MIN_VALUE; // Assigns minimum  int  value to min

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