三元條件運算符舉例

• 格式化代碼的快捷鍵ctrl+shift+f 自動導(dǎo)入：ctrl+shift+o
  import java.util.Scanner;
  public class Demo_1 {
  public static void main(String[] args) {
  // TODO Auto-generated method stub

    Scanner input = new Scanner(System.in);
    System.out.println("請輸入年份");
    //if-else 分支結(jié)構(gòu)--可以讓程序有多條執(zhí)行路徑
    if(input.hasNextInt()){
    int year = input.nextInt();
    
    if(year>0){
    boolean isLeapYear = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
    System.out.println(year + "年" + (isLeapYear ? "是" : "不是") + "閏年");
    input.close();
    }else{
        System.out.println("年份必須是正數(shù)");
    }
    
    }else{
        System.out.println("輸入錯誤！");
        }
     }
    }
  

分之結(jié)構(gòu)if else舉例

import java.util.Scanner;
public class Text3 {
        public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("請輸入x的值：");
    double x = input.nextDouble();
    double y;
    if(x<-1){
        y = 3 * x + 5;
    }else if (x<=1) {   //注意：else if表示已排除上面的條件了，既這里相當(dāng)于x>=-1&&x<1
        y = x - 1;
    }else {
        y = 5 * x - 3;
    }
    System.out.println("y= "+y);
    input.close();
}