在搜索CI中生成随机数的教程时发现了这个主题
当我尝试使用rand()
没有参数的函数时,我总是得到0.当我尝试使用rand()
带参数的函数时,我总是得到值41.每当我尝试使用arc4random()
和random()
函数时,我都会收到LNK2019错误.
这就是我所做的:
#include <stdlib.h>
int main()
{
int x;
x = rand(6);
printf("%d", x);
}
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这段代码总是生成41.我哪里错了?我正在运行Windows XP SP3并使用VS2010命令提示符作为编译器.
我正在尝试读取存储在*.ser文件中的所有对象,并将它们存储在一个对象数组中.如何获取存储在该文件中的对象数(这样我可以声明数组很number_of_objects
长)?
我检查了API,但无法找到理想的功能.
-edit-
部分代码:
Ser[] objTest2 = new Ser[number_of_objects];
for(int i=0; i<=number_of_objects, i++) {
objTest2[i] = (Ser)testOS2.readObject();
objTest2[i].printIt();
}
Run Code Online (Sandbox Code Playgroud) 这是我正在使用的代码:
public class splitText {
public static void main(String[] args) {
String x = "I lost my Phone. I shouldn't drive home alone";
String[] result = x.split(".");
for (String i : result) {
System.out.println(i);
}
}
}
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编译完美,但在运行时没有任何反应.我究竟做错了什么?
这是代码.
public class testClient {
public static void main(String[] args) {
testClient abc = new testClient();
abc.go();
}
public void go() {
try {
Socket s = new Socket("127.0.0.1", 5000);
InputStreamReader sr = new InputStreamReader(s.getInputStream());
BufferedReader reader = new BufferedReader(sr);
String x = reader.readLine();
System.out.println(x);
reader.close();
} catch(IOException ex) {
ex.printStackTrace();
}
}
}
public class testServer {
public static void main(String[] args) {
testServer server = new testServer();
server.go();
}
public void go() {
try {
ServerSocket s = …
Run Code Online (Sandbox Code Playgroud) 我在另一个类的实例方法中使用装饰器(类),如下所示:
class decorator_with_arguments(object):
def __init__(self, arg1=0, arg2=0, arg3=0):
self.arg1 = arg1
self.arg2 = arg2
self.arg3 = arg3
def __call__(self, f):
print("Inside __call__()")
def wrapped_f(*args):
print(f.__qualname__)
f(*args)
return wrapped_f
class Lol:
@decorator_with_arguments("hello")
def sayHello(self,a1, a2, a3, a4):
print(self.sayHello.__qualname__)
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现在,当我打印出来时,self.sayHello.__qualname__
它会打印decorator_with_arguments.__call__.<locals>.wrapped_f
有什么办法可以覆盖这个吗?我想在这里看到Lol.sayHello
(我的原始函数的全称)。
我尝试覆盖@property
__qualname__
of __call__
(使用静态字符串);没用。
首先,初学者在这里.
我正在使用此代码.
class MDArrays {
public static void main(String[] args) {
int[][] x;
int t=2;
x = new int[2][3];
for(int i=0; i<=1; i++) {
for(int j=0; i<=2; j++) {
x[i][j] = t;
t += 2;
System.out.println(x[i][j]);
}
}
}
}
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它编译得很完美,但在运行时,正确显示3个数字后,我收到以下错误.
Exception in thread "main" java.Lang.ArrayindexOutOfBoundsException : 3 at MDArrays.main(MDArrays.java:13)
我哪里错了?
我正在创建一些随机类来更好地理解多态性.编码如下:
Poly1:
public abstract class Poly1 {
int comPoly;
}
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SubPoly1:
public class SubPoly1 extends Poly1 {
String testPoly;
}
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SubPoly2:
public class SubPoly2 extends Poly1 {
int x;
}
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testPoly:
public class testPoly {
public static void main(String[] args) {
Poly1[] testObj = new Poly1[2];
testObj[0] = new SubPoly1();
testObj[1] = new SubPoly2();
testObj[1].x = 1;
testObj[1].comPoly = 2;
System.out.println("Test Output : " + testObj[1].x+ " and " + testObj[1].comPoly);
testObj[0].testPoly = "Hello";
testObj[0].comPoly = …
Run Code Online (Sandbox Code Playgroud) 这是代码:
public class Exc {
int x = 2;
public void throwE(int p) throws Excp, Excp2 {
if(x==p) {
throw new Excp();
}
else if(x==(p+2)) {
throw new Excp2();
}
}
}
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这是处理程序代码:
public class tdExc {
public static void main(String[] args) {
Exc testObj = new Exc();
try {
testObj.throwE(0);
System.out.println("This will never be printed, so sad...");
} catch(Exception Excp) {
System.out.println("Caught ya!");
} catch(Exception Excp2) {
System.out.println("Caught ya! Again!!!!");
} finally {
System.out.println("This will always be printed!");
} …
Run Code Online (Sandbox Code Playgroud) 这是我做过的第一个异常编码,猜测是什么,它产生了一个错误.伤心.
public class Exc {
int x = 2;
public void throwE(int p) throws Excp {
if(x==p) {
throw new Excp();
}
}
}
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我认为我不需要发布处理程序代码,因为即使这个类没有通过编译器.
我得到错误cannot find symbol
的Excp
.我完全按照书.有什么我想念的吗?
这是我正在使用的代码.
public class timerApp {
Runnable timerRun = new runX();
Thread thread1 = new Thread(timerRun);
public static void main(String[] args) {
timerApp xyz = new timerApp();
xyz.createGUI();
}
public void createGUI() {
JButton button = new JButton("Start timer");
JButton button2 = new JButton("Stop timer");
JFrame frame = new JFrame();
JLabel label = new JLabel("under_construction");
frame.getContentPane().add(BorderLayout.NORTH,button);
frame.getContentPane().add(BorderLayout.SOUTH,button2);
frame.getContentPane().add(BorderLayout.CENTER,label);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500,500);
frame.setVisible(true);
button.addActionListener(new b1L());
button2.addActionListener(new b2L());
}
public class b1L implements ActionListener {
public void actionPerformed(ActionEvent event) {
thread1.start();
}
}
public …
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