public class Pi {
public static void main(String[] args){
int a[] = new int[args.length];
for(int i=0;i<args.length;i++){
a[i] = Integer.parseInt(args[i]);
}
for(int j=0;j<a.length;j++){
System.out.println(a[j]);
}
}
}
public static void main(String[] args){
int a[] = new int[args.length];
for(int i=0;i<args.length;i++){
a[i] = Integer.parseInt(args[i]);
}
for(int j=0;j<a.length;j++){
System.out.println(a[j]);
}
}
}
总是有个(String[] args). 参数之间以空格分开。
象1楼那个java Pi 1 2 3
运行时,程序里就有了args这个字符串数组。args[0]="1",args[1]="2";args[3]="3";
args.length=3.
程序可直接使用了。
如果运行时不带参数,则args.length=0.
List<String> strings = new ArrayList<String>();
Scanner scan = new Scanner(System.in);
while(true){
System.out.println("请输出数字,输入exit结束输入:");
String s = scan.next();
if(s.equals("exit")){
break;
}
try {
Integer.valueOf(s);
strings.add(s);
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
int a[] = new int[strings.size()];
for (int i = 0; i < a.length; i++) {
a[i] = Integer.parseInt(strings.get(i));
}
for (int j = 0; j < a.length; j++) {
System.out.println(a[j]);
}
}
Scanner scan = new Scanner(System.in);
System.out.println(scan.next());
}
Scanner就提供接收键盘输入的
package ij;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Ws {
public static void main(String[] args) {
List<String> strings = new ArrayList<String>();
Scanner scan = new Scanner(System.in);
System.out.println("请输出数字,输入exit结束输入:");
while(true){
String s = scan.next();
if(s.equals("exit")){
break;
}
try {
Integer.valueOf(s);
strings.add(s);
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
int a[] = new int[strings.size()];
for (int i = 0; i < a.length; i++) {
a[i] = Integer.parseInt(strings.get(i));
}
for (int j = 0; j < a.length; j++) {
System.out.println(a[j]);
}
}
}