Java学习第五周

package com.sxt;

public class TestSwitch01 {
public static void main(String[] args) {
int grade=(int)(Math.random()*4)+1;// 大学的年级
switch (grade){
case 1:
System.out.println("大一");
break;
case 2:
System.out.println("大二");
break;
case 3:
System.out.println("大三");
break;
case 4:
System.out.println("大四");
break;
}
}
}
package com.sxt;

public class TestSwitch02 {
public static void main(String[] args) {
int month=(int)(Math.random()*12)+1;
switch (month) {
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
System.out.println(month+"月。属于上半年");
break;
default:
System.out.println(month+"月。术语下半年");
break;
}
}
}
package com.sxt;

public class Testwhlie {
public static void main(String[] args) {
int a = 0;
while(a<3){

		System.out.println("I love you!");
		a++;
	}
	int i=0;
	int sum =0;
	while(i<=100) {
	sum=sum+i;
	i++;
}
	System.out.println("1到100的和："+sum);
}	

}

public class TestFor {
public static void main(String[] args) {
int a = 0;//初始化部分
while(a<3){//布尔表达式

		System.out.println("I love you!");//循环体
		a++;//迭代因子
	}
	for(int a = 0;a<3;a++) {
		System.out.println("I love you!");
	}
}

}
package com.sxt;

public class Pring0_130By5 {
public static void main(String[] args) {
int i=1;
int count=0;//每行打印几个数
while(i<=130) {
System.out.println(i+"\t");
/if(i%5==0){
System.out.println();
}/
count++;
if(count==5) {
System.out.println();
count=0;
}
i++;
}
}
}