小编Eri*_*ans的帖子

#include <stdio.h>

int main(int argc, char **argv) {

int x[5][5] = {{0,1,2,3,4},{5,6,7,8,9}};

for (int i = 0; i < 4; i++) {
    for (int j = 0; i < 4; i++) {
        printf("%d\n", x[i][j]); } }

return 0; }

这本来应该给我:0 1 2 3 4 5 6 7 8 9

结果是:0 5 0 0

然后,当我将它们改为chars时:

#include <stdio.h>

int main(int argc, char **argv) {

char x[5][5] = {{'0','1','2','3','4'},{'5','6','7','8','9'}};

for (int i = 0; i < 4; i++) {
    for (int j = …

if (!(portField.getText().equals(""))) {                
    String p = portField.getText();
    CharSequence numbers = "0123456789";

    if (p.contains(numbers)) {

        listener = new ServerSocket(Integer.parseInt(p));

        while (true) {
            Socket socket = listener.accept();
            try {
                PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
                out.println("Hi there, human.");    
            } finally {
                socket.close(); 
            }
    }} else {
        JOptionPane.showMessageDialog(null, "Only numbers are allowed.");
    }
} else {
    JOptionPane.showMessageDialog(null, "Please input a port.");
}

问题是:JOptionPane弹出"只允许数字",即使我把数字放入portField.在CharSequence和我测试过它,只允许数字来输入,因为据我所知的方式,是正确的,和Java忽略了整个街区,并跳转到该else条款.

为什么会这样？我不应该使用else和使用else if吗？

这是run()方法:

public void run() {         
    ServerSocket listener = null;           
    if (running == true) {
        btnRun.setEnabled(false);
        try {
            if (!(portField.getText().equals(""))) {                
                String p = portField.getText();
                if (p.matches("[0-9]*")) {                          
                    listener = new ServerSocket(Integer.parseInt(p));                           
                    while (true) {
                        Socket socket = listener.accept();
                        try {
                            PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
                            out.println("Hi there, human.");    
                        } finally {
                            socket.close(); 
                        }
                    }
                } else {
                    JOptionPane.showMessageDialog(null, "Only numbers are allowed.");
                    btnRun.setEnabled(true);
                    running = 
                }
            } else {
                JOptionPane.showMessageDialog(null, "Please input a port.");
                btnRun.setEnabled(true);
                running = false;
            } …

我已经阅读了这篇好文章 作为参考,但我仍然无法解决我的循环问题:

import pygame
import python
import background
import player
import parser

class Game():

    map1 = parser.Parser("map1")
    map1.parse()

parser.py模块:

import os, sys

def replaceExtension(mapPath):

    # content

class Parser():

    def __init__(self, map, path="Maps/"):

        replaceExtension(path)

        # content

当我运行我的主文件时:

map1 = parser.Parser("map1")
AttributeError: 'module' object has no attribute 'Parser'

由于某些晦涩的原因,它只是找不到我的Parser类.

我有以下类和typedef:

class Object

{
protected:
    long int id;
public:
    Object(void);
    ~Object(void) {};
    long int get_id(void);
};

typedef map<string, Object> obj_map;

然后我有了它的孩子:

class Image: public Object

{
private:
    path full_path;
    int x;
    int y;
    img image;
public:
    Image(path p, int x_pos = 0, int y_pos = 0);
    ~Image(void) {};

    void draw(int flags = 0);
    void move_north(float velocity);
    void move_south(float velocity);
    void move_west(float velocity);
    void move_east(float velocity);

    path get_path(void);
    img get_image(void);
    int get_x(void);
    int get_y(void);
    void set_path(path p);
    void set_image(img _image);
    void …

我正在尝试实现一个消除字符串空格的函数。如果谓词仅显式过滤空格，我不明白为什么此列表推导式会消除第一个字符。

import Data.List
import System.IO

noSpace :: String -> String
noSpace (x:xs) = [x | x <- xs, x /= ' ']

main = do
  print(noSpace("8 j 8   mBliB8g  imjB8B8  jl  B"))

结果：

"j8mBliB8gimjB8B8jlB"

应该：

8j8mBliB8gimjB8B8jlB