Does pass by reference works in case of String In java if Objects are pass by reference than in following code,  String str1 = new String("abc"); String str2 = str1; str1 = str1+"def"; System.out.println("str2 : "+str2);   Even after modifying string str1 after assigning it to string str2 I get output as str2 : "abc" instead of "abcdef" so pass by reference does not work in case of string??
Is Java "pass-by-reference" or "pass-by-value"? 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?
Dell Vostro 5490 no WIFI in Ubuntu 18.04 Does Earth really have two high-tide bulges on opposite sides? The bit that makes sense – tidal forces My physics teacher explained that most tidal effect is caused by the Moon rotating around the Earth, and some also by the Sun. They said that in the Earth and Moon system, the bodies are in freefall about each other. But that points on the surface of Earth, not being at Earth's centre of gravity, experience a slightly different pulls towards the Moon. The pull is a little greater if they are on the Moon's side, and slightly lesser if they are on the side away from the Moon. Once freefall is removed, on the Moon side this feels like a pull towards the Moon and on the the opposite side it feels like a repulsion from the Moon. This makes sense to me, and is backed up by other questions and answers here, like  and also  Phys.SE question. The bit that doesn't make sense – tidal bulges They also said that there are &quot;tidal bulges&quot; on opposite sides of the Earth caused by these forces. The bulges stay still relative to the Moon and Earth rotating through the bulges explains why we get two tides a day. They drew a picture like this one…  An image search for  finds hundreds of similar examples, and  from a scientist on Twitter. …But, if there is a tidal bulge on both sides of Earth, like a big wave with two peaks going round and around, how can an island, like Great Britain where I live, simultaneously have a high tide on one side and a low tide on the other? For example:   on the West coast  on the East  Two ports with tides 6 hours, or 180º apart. It's high tide at one while low tide at the other. But they are only  by road. Great Britain is much smaller than Earth. It's probably not even as big as the letter &quot;A&quot; in the word &quot;TIDAL&quot; in that picture.  To prove this isn't just Britain being a crazy anomaly, here is another example from New Zealand:     Two ports that are 180º (6 hours) apart, but separated by  through a national park. New Zealand, unlike the UK, is in fairly open ocean. What does a "CALLBACK" declaration in C do? I was looking through some code from the  library and came across a function declared like this:  LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)   Now, I'm a Delphi coder.  No hablo C muy bien, senor.  But I remember enough syntax from my college courses to read it like this:  Function name is WndProc.  Argument list is pretty self-explanatory.  Function return type is LRESULT.  But what in the world is that "CALLBACK" doing there?  In Delphi, any function can be used as a callback; you just need to pass the right type of function pointer.  Is there any particular reason why C doesn't work that way?  Or does it mean something different? What is the difference between a "link function" and a "canonical link function" for GLM What's the difference between terms 'link function' and 'canonical link function'? Also, are there any (theoretical) advantages of using one over the other?  For example, a binary response variable can be modeled using many link functions such as logit, probit, etc. But, logit here is considered the "canonical" link function. I'm having some troubles understanding the solution (going from step $2$ to step $3$) of this linear congruence equation. Here's the problem with the solution:   Solve the congruence $2x + 11 \equiv 7 \pmod 3$.   First, we reduce all the coefficients $\pmod 3$:  $$2x + 2 \equiv 1 \pmod 3. \tag{1}$$  Next, we add $1$ to both sides, using the fact that $2 + 1 \equiv 0 \pmod 3$:  $$2x \equiv 2 \pmod 3. \tag{2}$$  Finally, we multiply both sides by $2$, using the fact that $2 · 2 = 4 \equiv 1 \pmod 3$:  $$x \equiv 1 \pmod 3. \tag{3}$$  That is, any number in the set $\{\ldots, −5, −2, 1, 4, \ldots\}$ will solve the original congruence.    Like I said my problem is the step between $(2)$ and $(3)$. If I multiply both sides of $(2)$ by $2$ I get:  $$4x \equiv 4 \pmod 3.$$  Now, I understand that $4$ is congruent to $1 \pmod 3$ so the RHS "simplifies" to $1 \pmod 3$ but I don't understand why the LHS "simplifies" to $x$. Can someone help me with this? Nothing happens when I press "Submit" on duplicate suggestion For example, in . The definite article implying the generic idea of something Remove Meta Privilege for MSE (only) Java - Could not find the main class If $p$ is congruent to $2 \pmod 3$, how can I prove that all $a$, $1 \le a \le p-1$ are cubic residues $\mod p$?  Here's what I've done:  $1^3$ congruent to $1 \pmod p$ thus, 1 is a cubic residue, Also $(p-1)^3=(p-1) \pmod p$ implies  $$(p-1)^3 - (p-1) = (p-1)[(p-1)^2 -1] = (p-1)(p^2 -2p) = p(p-1)(p-2) $$ implies $$p|(p-1)^3 -(p-1)$$ Thus  $p-1$ is a cubic residue $\mod p$. Now I don't know how to show for $1\lt a \lt p-1$ are all cubic residues when $p$ is congruent to $2\pmod 3$. How long can I store soaked beans before cooking? First order differential equations with 2 varriables Does anybody know how to solve the following differntial equation?  $$w^2\cdot r+\frac{dw}{dt}\cdot r+\frac{dr}{dt}\cdot w=3g$$  where w and r are a function of time so $w(t)$ and $r(t)$. $g$ is a constant  EDIT: This equation came from a thought problem of mine which I will now explain since I still do not know how to approach the problem.  Basically I want to design a spiral track in which a vehicle will accelerate. However the total acceleration needs to be constant.   The vehicle will have 2 acceleration components, a radial component ($a_r$) and a change in speed component ($a_s$). Since we want constant acceleration: $a_r + a_s = constant$  From circular motion we know that $a_r = \omega ^2 r$ where $r$ is the radius, and $\omega$    Further we know that $v=\omega*r$, therefore: $a_s=\frac{d}{dt}(\omega r)$  For constant acceleration $a_{total} = a_r + a_s = \omega ^2 r + \frac{d}{dt}(\omega r) =constant$  Further usefull information: Length of the track covered at a certain time $l=v*t=\omega r t$  With all this the radius will be a function of time, $r(t)$ and the angular velocity will be a function of time, $\omega (t)$  Boundary conditions: $r(0)  = 0$ $\omega (0) = 0$  Now I would like to find a possible set of solutions to create a track by implementing end boundary conditions that i choose e.g. $v(t_{end})=100 [m/s]$ and $l(t_{end})=5000 [m]$  Here is a diagram for clarity: Is it feasible to transform each variable differently while doing multiple regression How to prove a total order has a unique minimal element Let $R$ be a total order on set $S$. Prove that if $S$ has a minimal element, than the minimum element is unique.  I have difficulties with proofs. I know any graph of a total order is a straight line, which clearly has a minimal element. How doI tell when something is mathematically proven?  EDIT: this is how I would prove it  Let $x, y \in S$ such that x and y are minimal. Since S is a total order $x$ and $y$ are comparable and either    case 1: one comes after the other and therefore one isn't the minimal case 2: both are the same and $x=y$  I know this isn't a mathy argument and could use help making it more presentable. Where can I find sample or real Selenium projects. All the material I can find on github and on internet are basic, and never intermediate or advanced.  How does a real Selenium project look in real life? How can I find sample code? In almost every canon (that is, visual) source, Force users typically wave a hand to invoke the Force to move or manipulate objects, people and thoughts. I get out-of-universe this is a visual cue that the Force is being used, but in-universe is it strictly necessary?  (The only exception I can think of is when Luke is training on Dagobah and is balancing rocks while standing on one hand with Yoda on his foot. He doesn't appear to be waving his hand to move the rocks.)  Is this addressed anywhere in-universe, even in Legends? What changes with Kerberos authentication in IPv6 when everyone has a public IPv6 Address? How should Kerberos authentication be set up with IPv6?     What implications are there when client devices each use a public, globally routeable IPv6 IP address?  What changes when setup this way instead of using a NAT as was the norm with IPv4? How to add a Skype indicator? To change URL to user friendly URL I'm refactoring my ASP.net application from ASP.net 3.5 to 4.0. Also I'm changing the URLs to user friendly URLs /product.aspx?id=100 to /product-name/100.  All my pages are indexed by search engines and the site has already been online for 6 years. I'm planning to do 301 redirect from the old pages to the new one.  I want to make sure I won't lose the rankings and traffic.  Any suggestion how to do it properly? C# Lambda expressions: Why should I use them? I have quickly read over the  documentation.  This kind of example has helped me to understand better, though:   delegate int del(int i); del myDelegate = x =&gt; x * x; int j = myDelegate(5); //j = 25   Still, I don't understand why it's such an innovation. It's just a method that dies when the "method variable" ends, right? Why should I use this instead of a real method?