There are 8 Java basic data types, so just remember. Except that it's all reference type.
Java four class eight basic data types First class: integer byte short int long
Type II: float float double Class III: Logical Boolean (it has only two values desirable true false) Class Fourth: Character Char Data that can be allocated directly in the stack is the base data type.
Reference data type: is a reference to the data in the stack, but his object is in the heap.
To learn Java you must know where the various data are stored in memory.
A good understanding of memory can help you to analyze the program. Bytes:
Boolean Boolean 1/8
byte byte type 1
Char character type 21 characters can store a Chinese character
Short Quick-Integer 2
int integer Type 4
float float type (single precision) 4
Long length shaping 8
Double dual precision type (double) 8 The default integer type in Java is type int, and if you want to define float type, add L or L to the value.
The default float is also a double-precision floating point, and if you want to define float type, add F or F to the value. One byte equals 8 bits, one byte equals 256 digits, and that is 128 to 1271 altogether 256.
KB is Kbytes
Bytes is the meaning of "byte"!
K is the meaning of thousand, because the computer is calculated by binary, 10 1 is exactly 1024
1111111111 (binary) =1024 (decimal)
1Bytes (bytes) =8bit (bits)
An English letter or an Arabic numeral is a character that occupies a byte
A Chinese character is two characters and occupies two bytes.
Generally speaking the size is used bytes, uppercase "B", the network rate is used bit, attention is lowercase "b".
Example: A file has 8MBytes
Example: The rate at which I download files is 256kb/s, which is 2Mbit, which is usually the rate of our broadband Internet connection. Basic data Type Auto convert Byte->short,char, int, doubleint, floatlong, long floatRemember：small turn big, big turn little will lose precision!!! |
