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  • what is the point of escaping quotation marks in php

    - by Jacksta
    Here is a validation script from a book I am learning, Why is escaping the quotation marks necassery? e.g. <option value=\"char\">char</option> <?php //validate important input if ((!$_POST[table_name]) || (!$_POST[num_fields])) { header( "location: show_createtable.html"); exit; } //begin creating form for display $form_block = " <form action=\"do_createtable.php\" method=\"post\"> <input name=\"table_name\" type=\"hidden\" value=\"$_POST[table_name]\"> <table cellspacing=\"5\" cellpadding=\"5\"> <tr> <th>Field Name</th><th>Field Type</th><th>Table Length</th> </tr>"; //count from 0 until you reach the number fo fields for ($i = 0; $i <$_POST[num_fields]; $i++) { $form_block .=" <tr> <td align=center><input type=\"texr\" name=\"field name[]\" size=\"30\"></td> <td align=center> <select name=\"field_type[]\"> <option value=\"char\">char</option> <option value=\"date\">date</option> <option value=\"float\">float</option> <option value=\"int\">int</option> <option value=\"text\">text</option> <option value=\"varchar\">varchar</option> </select> </td> <td align=center><input type=\"text\" name=\"field_length[]\" size=\"5\"> </td> </tr>"; } //finish up the form $form_block .= " <tr> <td align=center colspan=3><input type =\"submit\" value=\"create table\"> </td> </tr> </table> </form>"; ?> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Create a database table: Step 2</title> </head> <body> <h1>defnie fields for <? echo "$_POST[table_name]"; ?> </h1> <? echo "$form_block"; ?> </body> </html>

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  • How to parse an XML file using PHP?

    - by Jack
    Here I have a variable 'response' which is obtained by parsing an XML file. $url = 'http://xxxxx.xml'; $ch = curl_init($url); $response = curl_exec($ch); The url structure is as follows - <user> <id>734</id> <name>Peter Parker</name> - <status> <favorited>false</favorited> </status> </user> How to access each bit of info like id,name,favorited from response?

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  • GoTo statements, and alternatives (help me please im new) (VB.net)

    - by qais
    Basically I posted a code snippet on a forum asking for help and people pointed out to me that using GoTo statements is very bad programming practise so I'm just wondering, why is it bad? And also what alternative is there to use, like for example in this program ive done for homework the user has to input their date of birth and if the month/date/year are invalid or unrealistic(using if statements checking the integer inputs size, if theres any better way to do this i'd appreciate if you could tell me that also :D) then how would i be able to loop back to ask them again? heres a little extract of my code retryday: Console.WriteLine("Please enter the day you were born : ") day = Console.ReadLine If day > 31 Or day < 1 Then Console.WriteLine("Please enter a valid day") GoTo retryday End If

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  • Awk: error in printf but not in print

    - by HH
    Works: awk '{print $$1"\t&\t"$$2"\t\\\\"}' .file > file.tex Does not work, why? awk '{printf %.2f"\t&\t"\.2f"\t\\\\",$$1,$$2}' .file > file.tex Error: awk: {printf %.2f"\t&\t"\.2f"\t\\\\",$1,$2} awk: ^ backslash not last character on line

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  • java source code doubt

    - by abson
    this compiles class ex1 { public int show() { try { int a=10/10; return 10;} catch(ArithmeticException e) { System.out.println(e); } finally { System.out.println("Finally");} System.out.println("hello"); return 20; } } on the other hand this doesn't class ex15 { public int show() { try { int a=10/0; return 10;} catch(ArithmeticException e) { System.out.println(e); } finally { System.out.println("Finally"); return 40;} System.out.println("hello"); return 20; } } why is it so?

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  • Java ArrayList initialization

    - by Jonathan
    I am aware that you can initialize an array during instantiation as follows: String[] names = new String[] {"Ryan", "Julie", "Bob"}; Is there a way to do the same thing with an ArrayList? Or must I add the contents individually with array.add()? Thanks, Jonathan

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  • Why is my simple recusive method's final return value always off by 1?

    - by FrankTheTank
    I'm attempting to create a text-based version of this game: http://www.cse.nd.edu/java/SameGame.html Here is the code I have so far: #include <iostream> #include <vector> #include <ctime> class Clickomania { public: Clickomania(); std::vector<std::vector<int> > board; int move(int, int); bool isSolved(); void print(); void pushDown(); bool isValid(); }; Clickomania::Clickomania() : board(12, std::vector<int>(8,0)) { srand((unsigned)time(0)); for(int i = 0; i < 12; i++) { for(int j = 0; j < 8; j++) { int color = (rand() % 3) + 1; board[i][j] = color; } } } void Clickomania::pushDown() { for(int i = 0; i < 8; i++) { for(int j = 0; j < 12; j++) { if (board[j][i] == 0) { for(int k = j; k > 0; k--) { board[k][i] = board[k-1][i]; } board[0][i] = 0; } } } } int Clickomania::move(int row, int col) { bool match = false; int totalMatches = 0; if (row > 12 || row < 0 || col > 8 || col < 0) { return 0; } int currentColor = board[row][col]; board[row][col] = 0; if ((row + 1) < 12) { if (board[row+1][col] == currentColor) { match = true; totalMatches++; totalMatches += move(row+1, col); } } if ((row - 1) >= 0) { if (board[row-1][col] == currentColor) { match = true; totalMatches++; totalMatches += move(row-1, col); } } if ((col + 1) < 8) { if (board[row][col+1] == currentColor) { match = true; totalMatches++; totalMatches += move(row, col+1); } } if ((col - 1) >= 0) { if (board[row][col-1] == currentColor) { match = true; totalMatches++; totalMatches += move(row, col-1); } } return totalMatches; } void Clickomania::print() { for(int i = 0; i < 12; i++) { for(int j = 0; j < 8; j++) { std::cout << board[i][j]; } std::cout << "\n"; } } int main() { Clickomania game; game.print(); int row; int col; std::cout << "Enter row: "; std::cin >> row; std::cout << "Enter col: "; std::cin >> col; int numDestroyed = game.move(row,col); game.print(); std::cout << "Destroyed: " << numDestroyed << "\n"; } The method that is giving me trouble is my "move" method. This method, given a pair of coordinates, should delete all the squares at that coordinate with the same number and likewise with all the squares with the same number connected to it. If you play the link I gave above you'll see how the deletion works on a click. int Clickomania::move(int row, int col) { bool match = false; int totalMatches = 0; if (row > 12 || row < 0 || col > 8 || col < 0) { return 0; } int currentColor = board[row][col]; board[row][col] = 0; if ((row + 1) < 12) { if (board[row+1][col] == currentColor) { match = true; totalMatches++; totalMatches += move(row+1, col); } } if ((row - 1) >= 0) { if (board[row-1][col] == currentColor) { match = true; totalMatches++; totalMatches += move(row-1, col); } } if ((col + 1) < 8) { if (board[row][col+1] == currentColor) { match = true; totalMatches++; totalMatches += move(row, col+1); } } if ((col - 1) >= 0) { if (board[row][col-1] == currentColor) { match = true; totalMatches++; totalMatches += move(row, col-1); } } return totalMatches; } My move() method above works fine, as in, it will delete the appropriate "blocks" and replace them with zeros. However, the number of destroyed (value returned) is always one off (too small). I believe this is because the first call of move() isn't being counted but I don't know how to differentiate between the first call or subsequent calls in that recursive method. How can I modify my move() method so it returns the correct number of destroyed blocks?

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  • For-loops in python

    - by Znarkus
    What is the best way of doing this in Python? for (v = n / 2 - 1; v >= 0; v--) I actually tried Google first, but as far as I can see the only solution would be to use while.

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  • Help with copy and deepcopy in Python

    - by Az
    Hi there, I think I tried to ask for far too much in my previous question so apologies for that. Let me lay out my situation in as simple a manner as I can this time. Basically, I've got a bunch of dictionaries that reference my objects, which are in turn mapped using SQLAlchemy. All fine with me. However, I want to make iterative changes to the contents of those dictionaries. The problem is that doing so will change the objects they reference---and using copy.copy() does no good since it only copies the references contained within the dictionary. Thus even if copied something, when I try to, say print the contents of the dictionary, I'll only get the latest updated values for the object. This is why I wanted to use copy.deepcopy() but that does not work with SQLAlchemy. Now I'm in a dilemma since I need to copy certain attributes of my object before making said iterative changes. In summary, I need to use SQLAlchemy and at the same time make sure I can have a copy of my object attributes when making changes so I don't change the referenced object itself. Any advice, help, suggestions, etc.?

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  • VB.net Cross-Thread

    - by PandaNL
    Hello, I have a cmd command that needs to be executed, when the command starts it starts to fill a progressbar. When the cmd command is done the progressbar needs to fill up to 100. This is the code i use, but it gives me an error when the progressbar.Value = 100 comes up. Public Class Form1 Dim teller As Integer Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerProgressbar.Tick teller += 1 ProgressBar1.Value = teller If ProgressBar1.Value = ProgressBar1.Maximum Then TimerProgressbar.Stop() End If End Sub This are the tow commands in another private sub where the app is crashing on ProgressBar1.Value = 100 TimerProgressbar.Stop() When i debug it and i try it out it crashes on ProgressBar1.Value = 100 But when i build it under Windows 7 it runs fine without crashing, however a few people reported me it crashes on there Windows xp system. VB gives me a suggestions about Cross Thread, but i don't know how i could make it work with this.

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  • Does code in the constructor add to code in subclass constructors?

    - by Jeremy Rudd
    Does code in the constructor add to code in subclass constructors? Or does the subclass's constructor override the superclass? Given this example superclass constructor: class Car{ function Car(){ trace("CAR") } } ...and this subclass constructor: class FordCar extends Car{ function FordCar(){ trace("FORD") } } When an instance of FordCar is created, will this trace "Car" and "Ford" ??

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  • How to draw a circle in java with a radius and points around the edge

    - by windopal
    Hi, I'm really stuck on how to go about programming this. I need to draw a circle within a JFrame with a radius and points around the circumference. i can mathematically calculate how to find the coordinates of the point around the edge but i cant seem to be able to program the circle. I am currently using a Ellipse2D method but that doesn't seem to work and doesn't return a radius, as under my understanding, it doesn't draw the circle from the center rather from a starting coordinate using a height and width. My current code is on a separate frame but i need to add it to my existing frame. import java.awt.*; import javax.swing.*; import java.awt.geom.*; public class circle extends JFrame { public circle() { super("circle"); setSize(410, 435); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Panel sp = new Panel(); Container content = getContentPane(); content.add(sp); setContentPane(content); setVisible(true); } public static void main (String args[]){ circle sign = new circle(); } } class Panel extends JPanel { public void paintComponent(Graphics comp) { super.paintComponent(comp); Graphics2D comp2D = (Graphics2D) comp; comp2D.setColor(Color.red); Ellipse2D.Float sign1 = new Ellipse2D.Float(0F, 0F, 350F, 350F); comp2D.fill(sign1); } }

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  • Frustration with generics

    - by sbi
    I have a bunch of functions which are currently overloaded to operate on int and string: bool foo(int); bool foo(string); bool bar(int); bool bar(string); void baz(int p); void baz(string p); I then have a bunch of functions taking 1, 2, 3, or 4 arguments of either int or string, which call the aforementioned functions: void g(int p1) { if(foo(p1)) baz(p1); } void g(string p1) { if(foo(p1)) baz(p1); } void g(int p2, int p2) { if(foo(p1)) baz(p1); if(bar(p2)) baz(p2); } void g(int p2, string p2) { if(foo(p1)) baz(p1); if(bar(p2)) baz(p2); } void g(string p2, int p2) { if(foo(p1)) baz(p1); if(bar(p2)) baz(p2); } void g(string p2, string p2) { if(foo(p1)) baz(p1); if(bar(p2)) baz(p2); } // etc. (The implementation of the g() family is just a placeholder. actually they are more complicated.) More types than the current int or string might have to be introduced at any time. The same goes for functions with more arguments than 4. The current number of identical functions is barely manageable. Add one more variant in either dimension and the combinatoric explosion will be so huge, it might blow away the application. In C++, I'd templatize g() and be done. I understand that .NET generics are different. <sigh> But I have been fighting them for two hours trying to come up with a solution that doesn't involve too much copy&paste of code. To no avail. Surely, C#/.NET/generics/whatever won't require me to type out identical code for a family of functions taking five arguments of either of three types? So what am I missing here?

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  • What is the single most influential book every programmer should read?

    - by NotMyself
    If you could go back in time and tell yourself to read a specific book at the beginning of your career as a developer, which book would it be? I expect this list to be varied and to cover a wide range of things. For me, the book would be Code Complete. After reading that book, I was able to get out of the immediate task mindset and begin to think about the bigger picture, quality and maintainability.

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  • How to parse XML file to get specific data effectively

    - by Carlos_Liu
    I have an XML file looks like this: <?xml version="1.0" encoding="utf-8" ?> <PathMasks> <Mask desc="Masks_X1"> <config id="01" mask="88" /> <config id="03" mask="80" /> <config id="51" mask="85" /> </Mask> <Mask desc="Masks_X2"> <config id="70" mask="1" /> <config id="73" mask="6" /> </Mask> <Types> <path id="01" desc="TC->PP1" /> <path id="02" desc="TC->PP2" /> <path id="03" desc="TC->PPn" /> </Types> </PathMasks> How to parse the file and get all the data of Mask_X1 as following: id value ===== 01, 88 03, 80 51, 85

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  • Java: how to access assignments in try-catch -loop?

    - by HH
    $ javac TestInit2.java TestInit2.java:13: variable unknown might not have been initialized System.out.println(unknown); ^ 1 error Code import java.util.*; import java.io.*; public class TestInit2 { public static void main(String[] args){ String unknown; try{ unknown="cannot see me, why?"; }catch(Exception e){ e.printStackTrace(); } System.out.println(unknown); } }

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  • side effect gotchas in python/numpy? horror stories and narrow escapes wanted

    - by shabbychef
    I am considering moving from Matlab to Python/numpy for data analysis and numerical simulations. I have used Matlab (and SML-NJ) for years, and am very comfortable in the functional environment without side effects (barring I/O), but am a little reluctant about the side effects in Python. Can people share their favorite gotchas regarding side effects, and if possible, how they got around them? As an example, I was a bit surprised when I tried the following code in Python: lofls = [[]] * 4 #an accident waiting to happen! lofls[0].append(7) #not what I was expecting... print lofls #gives [[7], [7], [7], [7]] #instead, I should have done this (I think) lofls = [[] for x in range(4)] lofls[0].append(7) #only appends to the first list print lofls #gives [[7], [], [], []] thanks in advance

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  • Need to add underscore to my regex

    - by TaMeR
    I suck at regular expression and just can't seem to figure this out. '/^[A-Za-z0-9](?:.[A-Za-z0-9]+)*$/' As it's right now it allows dots anytime after the first char and I like to add _ so that it allows both. Thanks

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  • Scrapy Could not find spider Error

    - by Nacari
    I have been trying to get a simple spider to run with scrapy, but keep getting the error: Could not find spider for domain:stackexchange.com when I run the code with the expression scrapy-ctl.py crawl stackexchange.com. The spider is as follow: from scrapy.spider import BaseSpider from __future__ import absolute_import class StackExchangeSpider(BaseSpider): domain_name = "stackexchange.com" start_urls = [ "http://www.stackexchange.com/", ] def parse(self, response): filename = response.url.split("/")[-2] open(filename, 'wb').write(response.body) SPIDER = StackExchangeSpider()` Another person posted almost the exact same problem months ago but did not say how they fixed it, http://stackoverflow.com/questions/1806990/scrapy-spider-is-not-working I have been following the turtorial exactly at http://doc.scrapy.org/intro/tutorial.html, and cannot figure out why it is not working.

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