Zhuo Jing---java Fundamentals 2

2. Data type

Basic type:

Integral type:

BYTE byte type 8 bit (bit) -2^7~2^7-1 ( -128~127) 0000 0000

Short 16-bit -2^15~2^15-1 ( -32768~32767)

int integer 32-bit -2^31~2^31-1 (approx. 2.1 billion)

Long 64-bit -2^63~2^63-1 (if you define a long type of data, you need to add L or L after the literal

Floating point type:

Float single-precision floating-point number 32-bit precision can only be 8 (note the following plus F or f)

Double dual-precision floating-point number 64-bit accuracy approx. 20 (plus D or D in the back)

Boolean: Boolean True or False

Character type: char expression: ASCII (0-127) Unicode (65,535 characters) GBK UTF-8 iso-8859-1.

Reference type: String, array, Object

Job: Enter a lowercase letter with the console, then capitalize (toUpperCase ()) and output. Before the conversion, it needs to be judged.

Zhuo Jing---java Fundamentals 2