Article 3: Basic Data Types of java

Data Type

I. Integer type

1. Decimal

2. Gossip

The number of octal segments is 8 to 1, including 0 ~ Add a "0" before the integer to indicate the number of octal digits.

3. hexadecimal

The hexadecimal number is full, and the value ranges from 0 to 1 ~ 9, ~ F, and add a "0x" before the integer to indicate the hexadecimal number.

Ii. Floating Point

1. float: Single-precision floating point number

When declaring a float-Type Floating Point Number, add F or f at the end.

2. double: double-precision floating point number

When declaring a floating point of the double type, add D or d at the end. The default floating point type is double, so D and d can also be excluded.

3. String (char)

Represents a character, 16 characters in two bytes

4. boolean)

Use true or false to indicate true or false

Type conversion

I. Free Conversion

You do not need to explicitly specify the type to be converted. Instead, it is automatically converted by the Java Virtual Machine.

Ii. Forced conversion

It is mandatory and cannot be automatically converted, but mandatory. Precision is lost.

Iii. implicit conversion

Similar to automatic conversion, the Java Virtual Machine determines whether the data type can be loaded based on the number of digits of the data type.