java怎样用if-elseif实现多条件判断 java多分支语句的基础教程

public class MultiCondition {
    public static void main(String[] args) {
        int score = 85;

        if (score >= 90) {
            System.out.println("优秀");
        } else if (score >= 80) {
            System.out.println("良好");
        } else if (score >= 70) {
            System.out.println("中等");
        } else if (score >= 60) {
            System.out.println("及格");
        } else {
            System.out.println("不及格");
        }
    }
}

score

if (score >= 90)

elseif (score >= 80)

score >= 60

score >= 80

||

int age = 25;
String gender = "male";

if (age >= 18 && gender.equals("male")) {
    System.out.println("成年男性");
} else if (age >= 18 && gender.equals("female")) {
    System.out.println("成年女性");
} else {
    System.out.println("未成年人");
}

int day = 3;
String dayName;

switch (day) {
    case 1:
        dayName = "Monday";
        break;
    case 2:
        dayName = "Tuesday";
        break;
    case 3:
        dayName = "Wednesday";
        break;
    case 4:
        dayName = "Thursday";
        break;
    case 5:
        dayName = "Friday";
        break;
    case 6:
        dayName = "Saturday";
        break;
    case 7:
        dayName = "Sunday";
        break;
    default:
        dayName = "Invalid day";
}

System.out.println(dayName); // 输出 "Wednesday"

day

default

int num = 5;

if (num > 10) {
    System.out.println("大于 10");
} else if (num < 0) {
    System.out.println("小于 0");
} // 没有 else 语句

num

public String getGrade(int score) {
    if (score >= 90) {
        return "A";
    } else if (score >= 80) {
        return "B";
    } else if (score >= 70) {
        return "C";
    } else if (score >= 60) {
        return "D";
    } else {
        return "F"; // 确保总是返回一个值
    }
}