Looping through an arraylist
How do I compare strings in Java?
Removing Firefox in Ubuntu with all add-ons like it never existed I have been using Firefox for a long time in Ubuntu, I downloaded some add-ons but it made firefox extremely slow, even if I remove them nothing will change.  I tried to remove Firefox also, but re-installing it will somehow recover the same Firefox I had- it seems it write some info somewhere that even if you remove Firefox, it will keep them.  Moreover, I am not able to use see any flash videos or website with Firefox(chrome works fine).. Honestly I tampered with plug-in settings in Firefox that this happened. But right now I can't do anything to overwrite the setting...  My question is how I can remove Firefox in a way to remove any previous traces and re-install a new version like for the first time? I am writing an article in English, with some pages in Russian.  \documentclass[12pt]{article}  \usepackage[T1,T2A]{fontenc}  \usepackage[utf8]{inputenc}  \usepackage[russian,english]{babel}  \usepackage{newtxmath} \usepackage{newtxtext} \begin{document}  hello \textbf{hello}  \selectlanguage{russian} привет \textbf{привет}  \end{document}   Output:  hello hello привет привет  I am using \selectlanguage{} to switch between languages when needed.  However, I noticed that when I try to use \textbf{} when in Russian language mode, it does not work because of newtxtext, which I am using for math formulas.  Does anyone know how to solve this problem?  Thank you. If $\sum{a_n}$ converges does that imply that $\sum{\frac{a_n}{n}}$ converges? I know if $\sum{a_n}$ converges absolutely then $\sum{\frac{a_n}{n}}$ converges since $0\le \frac{|a_n|}{n} \le |a_n| $ for all $n$ so it converges absolutely by the basic comparison test and therefore converges. However, I cannot prove the convergence of $\sum \frac{a_n}{n}$ if $\sum{a_n}$ converges but not absolutely even though I suspect it to be true. Can you give me a proof or a counterexample for this? Is it possible for information to be transmitted faster than light by using a rigid pole? Are there well known HTTP-only sites? Captive WIFI portals suck.  So often when I open in a browser (Desktop Chrome or Mobile Chrome) a HTTP site, I get the captive portal, but with auto-completion and so quickly I connect again to WIFI.  The problem is that after the captive portal redirects, I'll have also a HTTPS redirect and Chrome remember the certificate and to use only HTTPS.  So I cannot use the same site twice (in a session).  A well-known public HTTP only site will resolve this.  Well-known sites usually work, causing some less debugging of the WIFI connection. C state-machine design How prove there is no continuous functions $f:[0,1]\to \mathbb R$, such that $f(x)+f(x^2)=x$. Prove that there is no continuous functions $f:[0,1]\to R$, such that   $$ f(x)+f(x^2)=x. $$   My try. Assume that there is a continuous function with this property. Thus, for any $n\ge 1$ and all $x\in [0,1]$, \begin{align*} f(x)&amp;=x-f(x^2)=x-\big(x^2-f(x^4)\big)=x-x^2+\big(x^4-f(x^8)\big)=\cdots\\ &amp;=x-x^2+x^4-\cdots+(-1)^n\left(x^{2^n}-f\big(x^{2^{n+1}}\big)\right) \end{align*}  since $f(0)=0$ and $\displaystyle\lim_{n\to \infty}x^{2^{n+1}}=0$ for any $x\in(0,1)$,it follows by the continuity of $f$ that $\displaystyle\lim_{n\to \infty}f\big(x^{2^{n+1}}\big)=0$, hence $$f(x)=x-x^2+x^4-x^8+\cdots+(-1)^nx^{2^n}+\cdots$$ for any $x\in (0,1)$  Why do I have prove that there is exists such a continuous functions $f$? Maybe  my example is wrong? Why?  if my   method is wrong,then How prove this problem ? Thank you. I frequently find myself writing code like this:  List&lt;int&gt; list = new List&lt;int&gt; { 1, 3, 5 }; foreach (int i in list) {     Console.Write("{0}\t", i.ToString()); } Console.WriteLine();   Better would be something like this:  List&lt;int&gt; list = new List&lt;int&gt; { 1, 3, 5 }; Console.WriteLine("{0}\t", list);   I suspect there's some clever way of doing this, but I don't see it. Does anybody have a better solution than the first block? I applied to a program that I had been striving for in my undergrad, at a top school, but I've since felt overwhelmed with the thought of going this year. I think I should have waited until I was absolutely sure I could handle grad school emotionally and financially. I am so anxious now, thinking I've ruined my opportunity with this school if I don't go.   I am seriously considering withdrawing my application, but I'm very worried about how it might hurt me in the future when I reapply.  Otherwise I may have to decline if I am accepted and reapply. How to check type of variable in Java? Give an example of a convergent series $$\sum_{n=1}^{\infty}a_n$$ such that the series $$\sum_{n=1}^{\infty}a_{3n}$$ is divergent..  I cannot find find any kind of series... I am also be very thankful if you find a divergent series (changing the term convergent)... The score for the 4 questions are 111, 1218, 261 and 5 respectively, but they display 2 digits per line. This is an obvious bug in design. Subversion Obliterate feature I was just thinking of writing a shell script to implement the obliterate functionality in an easy to do way (externally, using the suggested way, but automated).  Here's what I had in mind:  On the client   svn list -R &gt; file-list. filter file-list in several ways like grep to create a file "files-to-delete", something like a set of grep XXX  file-list&gt;&gt;files-to-delete. transfer files-to-delete to the server using scp.   On the server   Dump the repository svnadmin dump /path/to/repos &gt; repos-dumpfile, this can be kept as a backup too. Filter the dump file, for each word in "files-to-delete", do: cat repos-dumpfile | svndumpfilter exclude $file &gt; new-dumpfile Create a new repository and load the new file to it svnadmin create new-name; svnadmin load new-name &lt; new-dumpfile   Would this work? How can it fail? Any other ideas? How can I change this method to query my master detail object? I am new to Apex trying to do some practice assignments and have gotten stuck on this junction object query.  Task: Edit the current getUser() method to do the following:  Return a custom object (that you define in the class) with the current getUser method's query data, and the list of teams the person belongs to (by querying the team assignments).   Parent Object 1: User (Standard Object) Parent Object 2: Team (Custom Object) Junction Object: Team Assignments (Custom Object)    **Original Class &amp; getUser Method** global class CTI {     global class CTIException extends Exception {}      global static User getUser() {          return [SELECT Id, Name, ProfileId, Profile.Name, UserRoleId, UserRole.Name, Username                  FROM User WHERE Id = :UserInfo.getUserId() ];     } } I've updated my Ubuntu to 19.10 couple of weeks ago and on installation system suggests to change or add shortcut for input source selection despite one was already defined previously. I've added ctrl+shift shortcut and just realized that it somehow overlapped any other ctrl+shift+something shortcuts globally, i.e. when I want to open new window in vscode, it opens new tab and it looks like system doesn't see the shift button press.   I tried to search this combination in shortcuts settings, but it's just not there. Run cmd.exe in Administrator mode without explorer.exe How to link to apps on the app store I am creating a free version of my iPhone game. I want to have a button inside the free version that takes people to the paid version in the app store. If I use a standard link    the iPhone opens Safari first, and then the app store. I have used other apps that open the app store directly, so I know it is possible.  Any ideas? What is the URL Scheme for the app store? Describe the equivalence classes in terms of familiar mathematical objects How can I take browser screenshots at a higher resolution than my browser supports? How to set English as default language instead of Tamil? The default language used in our laptop is Tamil. We don't know how to switch back to English. If we type something we are getting something.   We don't know the font name or version. Even the Menu bar and task bar contents are in Tamil.