刚学完JBuilder的前2章,课后有一题是:判断变量a值是正数还是负数,结果在屏幕上显示出来~~我写的代码如下:
public class ACost {
int a;
public static void main(String[] args) {
if (a > 0) {
System.out.println("a是正数");
}
else {
if (a < 0) {
System.out.println("a是负数");
}
else {
System.out.println("a为零");
}
}
}
}
这段代码很大问题,怎么写输入一个a值,哪个高手帮忙修改修改,谢谢!
另外想拜个师傅~~嘿嘿,有人愿意吗?
public class ACost {
int a;
public static void main(String[] args) {
if (a > 0) {
System.out.println("a是正数");
}
else {
if (a < 0) {
System.out.println("a是负数");
}
else {
System.out.println("a为零");
}
}
}
}
这段代码很大问题,怎么写输入一个a值,哪个高手帮忙修改修改,谢谢!
另外想拜个师傅~~嘿嘿,有人愿意吗?
a = Integer.parseInt(br.readLine());
import java.lang.*;
public class ACost {
public static void main(String[] args) {
try{
System.out.print("请输入数字a:");
BufferedReader stdin =new BufferedReader(new InputStreamReader(System.in));
String input=stdin.readLine();
while(input.length()>0&& !isInt(input)){
System.out.print("请输入数字a:");
stdin =new BufferedReader(new InputStreamReader(System.in));
input=stdin.readLine();
}
int a = Integer.parseInt(input);
if (a > 0) {
System.out.println("a是正数");
}
else {
if (a < 0) {
System.out.println("a是负数");
}
else {
System.out.println("a为零");
}
}
}catch(Exception e){
}
}
//判断输入字符串是否为数字
private static boolean isInt(String s) {
try {
Integer.parseInt(s);
return true;
} catch (NumberFormatException e) {
return false;
}
}
}
int a;
public static void main(String[] args) {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
a = Integer.parseInt(br.readLine());
if (a > 0) {
System.out.println("a是正数");
}
else {
if (a < 0) {
System.out.println("a是负数");
}
else {
System.out.println("a为零");
}
}
}
}
import java.io.IOException;
import java.io.InputStreamReader;/**
*
*//**
* @author ly
*
*/
public class ACost {
int a;
public static void main(String[] args) throws NumberFormatException, IOException {
int a;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
a = Integer.parseInt(br.readLine());
if (a > 0) {
System.out.println("a是正数");
}
else {
if (a < 0) {
System.out.println("a是负数");
}
else {
System.out.println("a为零");
}
}
}
}
byte b[]=new byte[30];
int n;
n=System.in.read(b);
//remove last two byte for 0x0A 0x0D
int a=Integer.parseInt(new String(b,0,n-2));
如果用图形方式的话,也可以用JOptionPane