java 学习（二）

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public class Scoure {   public static void main(String args[]) {       int score=90;       if (score>=85 && score <=100) {         System.out.println("优秀");     }else if (score>=65 && score <85) {         System.out.println("良");     }else if (score>=60 && score <65) {         System.out.println("及格");     }else if (score>=0 && score <60) {         System.out.println("不及格");     }else {         System.out.println("分数不能大于100 或者小于0");     } } } //if语句的练习

　　

public class lianxi {
public static void main(String args[]) {
    for (int i=100;i<201;i++){
        boolean b=false;
        for (int j=2;j<i-1;j++){
            int k =i%j;
            if (k==0){
                b=true;
            }
        }if (!b){
            System.out.println(i);
        }
    }
}
}
//寻找素数100-200

结果：

 

public class xing {
    public static void main(String args[]) {
        for (int i=1;i<5;i++){
            for (int j=0;j<4-i;j++){
                System.out.print((" "));
            }
            for (int k=0;k<i;k++){
                System.out.print("*  ");
            }
            
            System.out.println(" ");
        }
    }
}

运行结果

 

九九乘法口诀实现

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public class suanshu {      public static void main(String args[]) {         for (int i=0;i<10;i++){             for (int j=1;j<i+1;j++){                 System.out.print(String.format("%d*%d=%d",i, j,i*j));                 System.out.print(" ");             }             System.out.println(" ");         }     } }

　　

结果