java 关键字、标识符、自动类型转换

自动类型转换，将类型范围小的转到类型范围大的变量

package com.ithema.spedkey;

public class demo4 {
    
    
    public static void main(String[] args) {
    
    
        // 目标：理解自动类型转换
        byte a = 20;
        int b = a;
        System.out.println(a);
        System.out.println(b);

        int age = 12;
        double db = age;
        System.out.println(age);
        System.out.println(db);

        char ch = 'a';
        int code = ch;
        System.out.println(ch);
        System.out.println(code);
    }
}