public class Tabuada{
public static void main(String[] args) {
int i,j;
for(i=1;i<=9;i++) {
for(j=1;j<=i;j++) {
int s=i*j;
System.out.print(i+"×"+j+"="+s+"\t");
}
System.out.println();
}
}
}
设计一共程序,分别用循环控制计算1+1/2!+1/3!+…的前20项的和
public class Sum {
public static void main(String[] args) {
float sum=0;
float a=1;
for(int i=1;i<=20;i++) {
a=i*a;
sum=sum+1/a;
}
System.out.println(sum);
}
}
public class TestTV {
public static void main(String[] args) {
TV t = new TV();
t.currentState();
t.off();
t.channelUp(6);
t.volumeDown(5);
}
}
class TV {
String powerSwitch = "开";
int channel = 16;
int volume = 17;
public void currentState() {
System.out.println("电视机现在的状态是:"+"电源开关为:"+powerSwitch+" 频道为:"+channel+" 音量为:"+volume);
}
public void on() {
System.out.println("打开电视");
}
public void off() {
System.out.println("关闭电视");
}
public int channelDown(int decrement) {
int channel1=channel-decrement;
System.out.println("调节频道至:"+channel1);
return channel1;
}
public int channelUp(int increment) {
int channel2=channel+increment;
System.out.println("调节频道至:"+channel2);
return channel2;
}
public int volumeDown(int decrement) {
int volume1=volume - decrement;
System.out.println("调低音量至:"+volume1);
return volume1;
}
public int volumeUp(int increment) {
int volume2=volume + increment;
System.out.println("调高音量至:"+volume2);
return volume2;
}
}