public class testhello {
/**
* @param args
*/
public static void main(String[] args) {
int R=5;
System.out.println(R*R*3.14);
}
}
![](https://img2020.cnblogs.com/blog/2318733/202103/2318733-20210312110000443-881188019.png)
public class testhello {
/**
* @param args
*/
public static void main(String[] args) {
int f=60;
System.out.println((f-32)*5/9);
double c=15.555555;
System.out.println(c*9/5+32);
}
}
![](https://img2020.cnblogs.com/blog/2318733/202103/2318733-20210312110603934-164328457.png)
public class testhello {
/**
* @param args
*/
public static void main(String[] args) {
int a=5,b=8,x;
x=a;
a=b;
b=x;
System.out.println(a);
System.out.println(b);
}
}
![](https://img2020.cnblogs.com/blog/2318733/202103/2318733-20210312110917795-877435190.png)
public class testhello {
/**
* @param args
*/
public static void main(String[] args) {
int a=12345;
System.out.println(a/100*100);
}
}
![](https://img2020.cnblogs.com/blog/2318733/202103/2318733-20210312111149699-569965052.png)
public class testhello {
/**
* @param args
*/
public static void main(String[] args) {
int x,y,z,a=135;
x=a/100;
y=a/100%10;
z=a%10;
System.out.println(x+y+z);
}
}
![](https://img2020.cnblogs.com/blog/2318733/202103/2318733-20210312111424810-963008128.png)
public class testhello {
/**
* @param args
*/
public static void main(String[] args) {
char ch='A';
System.out.println((char)(ch+32));
char x='a';
System.out.println((char)(x-32));
}
}
![](https://img2020.cnblogs.com/blog/2318733/202103/2318733-20210312112828160-527526020.png)