Search Results

Search found 6442 results on 258 pages for 'beginner programmer'.

Page 66/258 | < Previous Page | 62 63 64 65 66 67 68 69 70 71 72 73  | Next Page >

  • Java NullPointerException. Why?

    - by user292844
    I am new to Java. I just read that class variables in Java have default value. I tried the following program. I was expecting to get the output as 0, which is the default value on an integer, but I get the NullPointerException. What am I missing? class Test{ static Integer iVar; public static void main(String...args) { System.out.println(iVar.intValue()); } }

    Read the article

  • howto Debugging on PHP

    - by justjoe
    how we do basic debugging in PHP ? Can anybody share true horror story on debugging PHP application (or (even better) on PHP framework such Codeigniter and Wordpress) ? i love to hear real experience in case i have to encounter similar situation on my journey to learn PHP.

    Read the article

  • How did you learn to be a programming guru?

    - by Xonara
    College courses are obviously very helpful, but I hear all the time about great programmers that just "taught themselves," and I wonder how the hell they did it. Online tutorials are nice - online support, even better - but learning with nothing but online resources is difficult to say the least, and I don't know anybody that's experienced enough to help me learn. Even if I did, they probably wouldn't have the time for it. Any advice is greatly appreciated. Becoming an application/game designer is something I've wanted to achieve for a long, long time, even if I never use it for a career, and it does mean alot to me. However, I'm constantly thwarted by lack of motivation, or perhaps confidence. Though I've found some good tutorials online, sometimes I feel it just isn't enough to really get me somewhere, and my limited knowledge of computers (and any other technology) in general is hardly reassuring. I'm constantly getting the feeling that maybe it isn't "in me." Well, guess that's it. I just don't want to join the legions of aspiring techies that just gave up.

    Read the article

  • Setting the rank of a user-defined verb in J

    - by Gregory Higley
    Here's a function to calculate the digital sum of a number in J: digitalSum =: +/@:("."0)@": If I use b. to query the rank of this verb, I get _ 1 _, i.e., infinite. (We can ignore the dyadic case since digitalSum is not dyadic.) I would like the monadic rank of this verb to be 0, as reported by b.. The only way I know of to do this is to use a "shim", e.g., ds =: +/@:("."0)@": digitalSum =: ds"0 This works great, but I want to know whether it's the only way to do this, or if there's something else I'm missing.

    Read the article

  • how to see contents of a.out file?

    - by abhilashm86
    The executable file of c++ will contain linkers, modules and others, i would like to look into its contents, i'm using linux, how can i view contents of a.out? which command should use to browse a.out, text editors wont show the contents......

    Read the article

  • [solved] What's wrong with this jQuery example?

    - by Sven Larson
    The following jQuery example should put some text into the div, but it doesn't. I tried Firefox, Google Chrome and Internet Explorer. <html> <head> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" language="javascript"></script> <script language="javascript"> $(window).load(function() { $('adiv').html('<p>hello world</p>'); alert('done'); }); </script> </head> <body> <div id="adiv"> </div> </body> </html> Sorry, this might be stupid, but I'm stuck.

    Read the article

  • What's the Difference Between These Two Ruby Class Initialization Definitions?

    - by michaelmichael
    I'm working through a book on Ruby, and the author used a slightly different form for writing a class initialization definition than he has in previous sections of the book. It looks like this: class Ticket attr_accessor :venue, :date def initialize(venue, date) self.venue = venue self.date = date end end In previous sections of the book, it would've been defined like this: class Ticket attr_accessor :venue, :date def initialize(venue, date) @venue = venue @date = date end end Is there any functional difference between using the setter method, as in the first example, vs. using the instance variable as in the second? They both seem to work. Even mixing them up works: class Ticket attr_accessor :venue, :date def initialize(venue, date) @venue = venue self.date = date end end

    Read the article

  • how to start learning JavaScript

    - by antriksh
    Dear All, I am experienced in the technical support like Linux, oracle, sunos etc and but if i say scripting i know little bit of bash. Now i promoted to manage technical engineers including some JavaScript developers, so i want to learn JavaScripting so that i can understand engineers. Hope you understand. Can you please advise me how can i start JavaScripting and point me to some simple docs and examples.

    Read the article

  • C++: calling member functions within constructor?

    - by powerboy
    The following code raises a runtime error: #include <iostream> #include <iterator> #include <ext/slist> class IntList : public __gnu_cxx::slist<int> { public: typedef IntList::iterator iterator; IntList() { tail_ = begin(); } // seems that there is a problem here void append(const int node) { tail_ = insert_after(tail_, node); } private: iterator tail_; }; int main() { IntList list; list.append(1); list.append(2); list.append(3); for (IntList::iterator i = list.begin(); i != list.end(); ++i) { std::cout << *i << " "; } return 0; } Seems that the problem is in the constructor IntList(). Is it because it calls the member function begin()?

    Read the article

  • extract variables from an expression using javascript regexp

    - by powerboy
    For example, here is a string representing an expression: var str = 'total = sum(price * qty) * 1.09875'; I want to extract variables (i.e., 'total', 'price' and 'qty' but not 'sum' since 'sum' is a function name) from this expression. What is the regexp pattern in javascript? Variable name consists of letters, digits, or the underscore, beginning with letters or the underscore.

    Read the article

  • Array of function pointers in Java

    - by Waltzy
    I have read this question and I'm still not sure whether it is possible to keep pointers to methods in an array in Java, if anyone knows if this is possible or not it would be a real help. I'm trying to find an elegant solution of keeping a list of Strings and associated functions without writing a mess of hundreds of 'if's. Cheers edit- 'functions' changed to 'methods', seems to bug people.

    Read the article

  • Get information about a function in python, looking at source code

    - by Werner
    Hi, the following code comes from the matplotlib gallery: #!/usr/bin/env python from pylab import * x = array([10, 8, 13, 9, 11, 14, 6, 4, 12, 7, 5]) y = array([8.04, 6.95, 7.58, 8.81, 8.33, 9.96, 7.24, 4.26, 10.84, 4.82, 5.68]) I am new to python, and would like to change the content of x and y from an input file. I have two short questions: I could guess what array means, but once I see it on the code, how can I know to which library it belongs and more information about it? Should I use some kind of python debug commands? How do I insert the content of my input file into x? Thanks

    Read the article

  • removing elements incrementally from a list

    - by Javier
    Dear all, I've a list of float numbers and I would like to delete incrementally a set of elements in a given range of indexes, sth. like: for j in range(beginIndex, endIndex+1): print ("remove [%d] => val: %g" % (j, myList[j])) del myList[j] However, since I'm iterating over the same list, the indexes (range) are not valid any more for the new list. Does anybody has some suggestions on how to delete the elements properly? Best wishes

    Read the article

  • Why does initWithFrame have the wrong frame value?

    - by greypoint
    I have a subclass of UIButton called INMenuCard and I am overriding the initWithFrame to include an activity indicator. The menuCard places correctly but any internal reference to "frame" give me "inf,inf,0,0" which means my activityIndicator subview is not placed correctly. What might I be missing? @implementation INMenuCard - (id)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) { CGRect innerFrame = CGRectInset(frame, 50.0f, 100.0f); activityIndicator = [[UIActivityIndicatorView alloc] initWithFrame:innerFrame]; activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhite; [self addSubview:activityIndicator]; } return self; } I am instantiating INMenuCard with (debugging shows the CGRect values are correct): CGRect cardFrame = CGRectMake(cardX, cardStartY, cardWidth, cardHeight); INMenuCard *menuCard = [[INMenuCard buttonWithType:UIButtonTypeCustom] initWithFrame:cardFrame]; [theView addSubView:menuCard];

    Read the article

  • reading csv file without for

    - by Abruzzo Forte e Gentile
    Hi All I need to read a CSV file in python. Since for last row I receive a 'NULL byte' error I would like to avoid using for keyword but the while. Do you know how to do that? reader = csv.reader( file ) for row in reader # I have an error at this line # do whatever with row I want to substitute the for-loop with a while-loop so that I can check if the row is NULL or not. What is the function for reading a single row in the CSV module? Thanks Thanks p.S. below the traceback Traceback (most recent call last): File "FetchNeuro_TodayTrades.py", line 189, in for row in reader: _csv.Error: line contains NULL byte

    Read the article

  • Importing data from file to array

    - by stamp
    I have 2 dimensional table in file, which look like this: 11, 12, 13, 14, 15 21, 22, 23, 24, 25 I want it to be imported in 2 dimensional array. I wrote this code: INTEGER :: SMALL(10) DO I = 1, 3 READ(UNIT=10, FMT='(5I4)') SMALL WRITE(UNIT=*, FMT='(6X,5I4)') SMALL ENDDO But it imports everything in one dimensional array.

    Read the article

  • How do I set up my @product=Product.find(params[:id]) to have a product_url?

    - by montooner
    Trying to recreate { script/generate scaffold }, and I've gotten thru a number of Rails basics. I suspect that I need to configure default product url somewhere. But where do I do this? Setup: Have: def edit { @product=Product.find(params[:id]) } Have edit.html.erb, with an edit form posting to action = :create Have def create { ... }, with the code redirect_to(@product, ...) Getting error: undefined method `product_url' for #< ProductsController:0x56102b0 My def update: def update @product = Product.find(params[:id]) respond_to do |format| if @product.update_attributes(params[:product]) format.html { redirect_to(@product, :notice => 'Product was successfully updated.') } format.xml { head :ok } else format.html { render :action => "edit" } format.xml { render :xml => @product.errors, :status => :unprocessable_entity } end end end

    Read the article

< Previous Page | 62 63 64 65 66 67 68 69 70 71 72 73  | Next Page >