1、第一个Java程序
package learnJava;
public class Learn1 {
public static void main(String[] args) {
System.out.print("Hello World");
}
}
2、变量与计算
package learnJava;
import java.util.Scanner;
public class Learn1 {
public static void main(String[] args) {
System.out.println("Hello World");
Scanner in = new Scanner(System.in);
int price = 0;
int amount = 0;
System.out.println("请输入票面:");
amount = in.nextInt();
System.out.println("请输入金额");
price = in.nextInt();
System.out.println(amount+"-"+price+"="+(amount-price));
}
}
3、浮点数计算
package learnJava;
import java.util.Scanner;
public class learn_float {
public static void main(String[] args) {
int foot;
double inch;
Scanner in = new Scanner(System.in);
foot = in.nextInt();
inch = in.nextDouble();
System.out.println("foot="+foot+",inch="+inch);
System.out.println((foot+inch/12)*0.3048);
}
}
4、运算符的优先级
5、强制类型转化
package learnJava;
import java.util.Scanner;
public class learn_float {
public static void main(String[] args) {
int foot;
double inch;
foot = (int)(30/3.0);
Scanner in = new Scanner(System.in);
foot = in.nextInt();
inch = in.nextInt();
System.out.println("foot="+foot+",inch="+inch);
System.out.println((int)(foot+inch/12)*0.3048*100+"cm");
}
}