I know that String is immutable and it's value can't be changed, but why does the value of the below StringBuffer doesn't change when sent like a method parameter. From my understanding it should have changed with the new value "bb". Thank you for your help.   class Ideone {      public static void main (String[] args) {          String s = "aa";         StringBuffer sb = new StringBuffer("aa");         modify(s, "bb");         modify2(sb, "bb");         System.out.println(s);         System.out.println(sb);     }      public static void modify(String s, String ss) {         s = ss;     }      public static void modify2(StringBuffer sb, String ss) {         sb = new StringBuffer(ss);     } }
I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?
I made a script that should notify me when there's a new chapter of manga that I'm reading. I used the command notify-send to do this. The program works when I am trying to run it in terminal. The notification is showing. However, when I placed this in my crontab, the notification doesn't show. I'm pretty sure that the program is running since I made it to create a file for me. The file was created, but the notification didn't show.  Here's my script  #!/bin/bash    #One Piece Manga reminder     #I created a file named .newop that contains the latest chapter.     let new=$(cat ~/.newop)     wget --read-timeout=30 -t20 -O .opreminder.txt http://www.mangareader.net/103/one-piece.html  if (( $(cat .opreminder.txt | grep "One Piece $new" | wc -l) &gt;=1 ))     then         (( new+=1 ))         echo $new         echo $new &gt; ~/.newop         notify-send "A new chapter of One Piece was released."     else         notify-send "No new chapter for One Piece."         notify-send "The latest chapter is still $new."     fi         exit   And here's what I wrote in my crontab  0,15,30,45 12-23 * * 3   /home/jchester/bin/opreminder.sh GitHub pages are not updating How to install Hp laser jet 1020 plus printer? I have been playing with the settings for the text object recently, and every time I add a new text object, I need to change the font to my favorite one. (Eurostile LT ExtendedTwo) Is there any way to change the default font so I do not need to change it every time I add a new text object?   Example: Bullied boy given immense powers by an alien race who destroys the human race Did all Headmasters get a portrait in Hogwarts? Throughout the Harry Potter series, we see that deceased Headmasters of the school get a semi-sentient portrait of themselves in the Headmaster's Office, at the service of the current Headmaster. Do all Headmasters get a portrait? What are the conditions of getting one? For instance, there are a couple of times when Dumbledore is temporarily deposed as Headmaster: Dolores Umbridge takes over the job in Order of the Phoenix, and Minerva McGonagall takes the job in Chamber of Secrets and Half Blood Prince. Will Umbridge and McGonagall have portraits in the Headmaster's Office when they expire? Proximal Operator Fixed Point Property for Matrices $\newcommand{\prox}{\operatorname{prox}}$ $\newcommand{\argmin}{\operatorname{argmin}}$ $\newcommand{\dom}{\operatorname{dom}}$  Recall again that the proximal operator for vectors $\prox_{f}: R^n \rightarrow R^n$ of $f$ is defined as:  $\prox_f(v) := \argmin_{x} \left(f(x) +(1/2)\|x-v\|_2^2 \right) $,  where $f: R^n \rightarrow R \cup \infty$ is a closed proper convex function and $\|\cdot \|_2$ is the Euclidean norm. $\prox$ is strongly convex and not everywhere infinite, so there it will have a unique minimizer for every $v \in R^n$  The crucial property of proximal operator is that $x^*$ minimizes $f(x)$ iff $x^* = \prox_f(x^*)$, i.e. $x^*$ is a fixed point of $\prox_f$.  Let us consider the proof of this property. The first part, namely, that if $x^*$ minimizes $f$ then $\prox_f(x^*)=x^*$, is trivial:  $f(x) +(1/2)\|x-x^*\|_2^2 \le f(x^*) = f(x^*) +(1/2)\|x^*-x^*\|_2^2$  The second part uses the notion of subdifferential. In the proof authors say that $\tilde{x}$ minimizes  $f(x) +(1/2)\|x-v\|_2^2$  i.e. $\tilde{x} = \prox_f(v)$ iff $0 \in \partial f(\tilde{x}) + (\tilde{x}-v)$,   where the sum is of a set and a point. Recall the definition of the subdifferential:  $\partial f(x) = \{ y$ |  $ f(z)\le f(x) + y^T(z-x)$ $\forall z \in \dom{f}\}$  Take $\tilde{x}=v=x^*$, it follows that $0 \in \partial f(x^*)$ so $x^*$ minimizes $f$.  Question 1:  Consider proximal operator defined for matrices now:  $\prox_f(Y) := \argmin_{X} \left(f(X) +(1/2)\|X-Y\|^2 \right)$,  where $X$ is some real $m$ by $n$ matrix. What norm function should be taken in the definition of the $\prox$ in this case? Frobenius? Or spectral norm (induced 2nd norm) which is the largest eigenvalue (is spectral norm even differentiable?)? Or something else?  Question 2:   Can the norm for the definition of $\prox$ in case of matrices be chosen in different ways? What conditions does the proof above impose on the norm function? How can I SSH with a remote server so I can browse files and edit them? I have a username and password to use. Dynamic trigger creation from managed package I have a requirement to create triggers dynamically after a managed package is installed. I have read that the tooling API can be used to create triggers dynamically however it cannot be used in production. Is it possible to create triggers from a managed package in an org? I want to be able to create the trigger based on some user inputs. Every Function in a Finite Field is a Polynomial Function How do Idle games progress while not active? I no longer need an answer to a question; what should I do to the question? Unexpected workspace change? My friend who has only recently downloaded blender has come across a workspace issue. He said he accidentally pressed a button and it has entirely changed his user interface/ Workspace. He can't open, save or do anything with the change.    This is a full window image! What is $\mathbb{E}[W(s)\mathrm{e}^{W(S)}]$ where W(S) is a standard Brownian Motion? I know that since it is a Brownian motion that $W(s)\sim{N(0,s)}$. One approach I tried, was to see that $W(s)-W(0)\sim N(0,1)$ and to let $X = W(s)$ and then solve $\mathbb{E}[X\mathrm{e}^X]$ but I end up with some awful integral. I was wondering whether there was an easier way? Or perhaps a simple way to solve this integral: $\int_{-\infty}^{\infty} \frac{1}{\sqrt{2{\pi}s}}x\mathbb{e}^{x}\mathbb{e}^{-\frac{x^2}{2s}}$ Hot chicken soup takes hours to cool I made a big pot of a very hot chicken soup. I put it in my small extra fridge at 11 PM, and it was still warm 9 hours later, at 8 AM.  Do I need to throw it away? Prove that every prime larger than $3$ gives a remainder of $1$ or $5$ if divided by $6$ Can we prove that every prime larger than $3$ gives a remainder of $1$ or $5$ if divided by $6$ and if so, which formulas can be used while proving? How do I debug Node.js applications? Explain proof by contradiction. Print lines between (and excluding) two patterns When conducting a t-test why would one prefer to assume (or test for) equal variances rather than always use a Welch approximation of the df? It seems like when the assumption of homogeneity of variance is met that the results from a Welch adjusted t-test and a standard t-test are approximately the same.  Why not simply always use the Welch adjusted t?