Day6 (What is the eight basic data types of data types byte)

type of data

Strongly typed language
requires the use of variables to strictly comply with regulations, and all variables must be defined before they can be used

Java data types are divided into two categories

Primitive type

        //四个整数类型
        int num1 = 999;
        //int 占四个字节范围
        //int 最常用9
        byte num2 = 9;
        //byte 占一个字节范围 -128到127
        short num3 = 99;
        long num4 = 99999L;// long类型要在数字后面加L（大写）

        //小数 浮点数：
        float num5 = 9.9F;// float类型要在数字后面加F
        double num6 = 9.99;//常用

        //字符（字符代表的是一个字，两个字就不是了，两个字是字符串）
        char name = '瓜';// 用这个'‘引号 占2个字节
        //字符串
        //Sting不是关键字，是类

        //布尔值 (是，非)
        boolean summer = true;
        boolean winter = false;

Reference data type (reference type)

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What is byte

Bit (bit) The smallest unit of internal data storage. 11001100 is an eight-bit binary
byte (byte) basic unit of data processing. It is customary to use capital B to represent
1B (byte, byte) = 8bit (bit)
character: Yes Refers to letters, numbers, words and symbols used in computers

1bit means 1 bit,
1Byte means a byte 1B=8b
1024B=1KB
1024KB=1M
1024M=1G
1024G=1T