Java零基础入门到精通

Java零基础入门到精通_Day 2

news2025/10/31 19:22:08

18 算数运算符

+ - * / % 整数的运算只能得到整数除非用浮点数进行运算（得到浮点数）

public class Base_002 {
    public static void main(String[] args) {
        double a  = 6.0;
        int b =4;
        System.out.println(a/b); //1.5
    }
}

19 字符的+操作

public class Base_002 {
    public static void main(String[] args) {
        int a =4;
        char b = 'A'; //65
        char c = 'a'; //97
        char d = '0'; //48
        System.out.println(a+b); //69
        System.out.println(a+c); //101
        System.out.println(a+d); // 52

//        char ch =a+c; //自定变为int类型
        int ch =a+c;
        System.out.println(ch); //101
//        int k = 10+12.1; //报错
        double k = 10+12.1; //报错
        System.out.println(k); //22.1
    }
}

20 字符串的+操作

public class Base_002 {
    public static void main(String[] args) {
        System.out.println("it "+"heima");
        System.out.println("heima"+666);
        System.out.println(666+"heima");
        System.out.println("heima"+6+44);
        System.out.println(4+6+"heima");
        System.out.println("33"+"22"+"sss");
//        it heima
//        heima666
//        666heima
//        heima644
//        10heima
//        3322sss

    }
}

21 赋值运算符

public class Base_002 {
    public static void main(String[] args) {
        short s =10;
        s +=10;
        System.out.println(s);
//        s = s+10; //报错不兼容的类型
        s = (short) (s+10);
        System.out.println(s);
    }
}

22 自增自减运算符

public class Base_002 {
    public static void main(String[] args) {
        int i =10;
        int j = i++;
        System.out.println(i); //11
        System.out.println(j); //10
    }
}

23 关系运算符

24 逻辑运算符号

25 短路逻辑运算符

26 三元运算符

public class Base_002 {
    public static void main(String[] args) {
        int a = 10;
        int b = 20;
        int max = a > b ? a : b;
        System.out.println(max); //20

    }
}

27 两只老虎

略

(w1==w2)? true:flase

28 三个和尚

public class Base_002 {
    public static void main(String[] args) {
        int a = 10;
        int b = 20;
        int c = 15;
        int max = (a>b)? a:b ;
        int maxx = (max > c) ? max:c;
        System.out.println(maxx);

    }
}

29 数据输入

import java.util.Scanner;
public class Base_002 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int i = scanner.nextInt();
        System.out.println(i);
    }
}