The following while loop within the program I'm writing is not being entered into, even though the condition within parentheses would evaluate as true (as far as I can tell). Here is the loop with the assignment before it:  String choose = "y";   while(choose=="y");  {      System.out.println("Enter 4-digit time: (0000 - 2359)");      String time_ = s.nextLine();      System.out.println("Angle between hour hand and minute hand is: " + timeToAngle(time_) + " degrees");      System.out.println("Would you like to calculate the angle for another time? (y/n)");      choose = s.next();   }   Please could somebody give me a pointer in the right direction? This is driving me crazy
93
I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?
40567
I'm working on a project where i find i'm checking for the following in many, many places:  if(item.Rate == 0 || item.Rate == null) { }   more as a curiousity than anything, what's the best way to check for both cases?  I've added a helper method which is:  public static bool nz(object obj) {     var parsedInt = 0;     var parsed = int.TryParse(obj.ToString(), out parsedInt);     return IsNull(obj) || (parsed &amp;&amp; parsedInt == 0); }   Is there a better way?
9683
Hey all I asked this over  =) and I got a good answer but I still have no idea whats going on. I want to know how the expression got to the answer and maybe the math behind how it was reasoned.. the steps if you would be so kind. The likelihood is I don't understand the equation.   I'm not a big maths person please be gentle :p     For all those playing along at home I'm reading Absolute Java 5th   Edition by Walter Savitch (Chapter 2 Page 66).      The Expression  double d = 12345.123456789; System.out.printf("START%12.5e END %n", d);       The Answer  START 1.23451e+04END       I understand the basic principles of this printf method's arguments   for example I know the '%' represents the start of the parameters.   '12' is the number of spacing, '.5' is the times the decimal point   will move.... I see the decimal point has moved 4 places towards the   left... can someone explain the principles of e-notation. Also how   this expression came to this answer =).      As far as e-notation go's its meant to be scientific notation;      So like 5.89e-4 would mean 0.000589 (move the decimal place if minus   left if not move the decimal place right).
90864
I very rarely meet any other programmers!  My thought when I first saw the token was "implies that" since that's what it would read it as in a mathematical proof but that clearly isn't its sense.  So how do I say or read "=>" as in:-  IEnumerable&lt;Person&gt; Adults = people.Where(p =&gt; p.Age &gt; 16)   Or is there even an agreed way of saying it?
61002
for (i=0 ; i&lt;=10; i++) {     ..     .. }  i=0; while(i&lt;=10) {     ..     ..     i++; }   In for and while loop, which one is better, performance wise?
37260
In C# and in Java (and possibly other languages as well), variables declared in a "try" block are not in scope in the corresponding "catch" or "finally" blocks.  For example, the following code does not compile:  try {   String s = "test";   // (more code...) } catch {   Console.Out.WriteLine(s);  //Java fans: think "System.out.println" here instead }   In this code, a compile-time error occurs on the reference to s in the catch block, because s is only in scope in the try block.  (In Java, the compile error is "s cannot be resolved"; in C#, it's "The name 's' does not exist in the current context".)  The general solution to this issue seems to be to instead declare variables just before the try block, instead of within the try block:  String s; try {   s = "test";   // (more code...) } catch {   Console.Out.WriteLine(s);  //Java fans: think "System.out.println" here instead }   However, at least to me, (1) this feels like a clunky solution, and (2) it results in the variables having a larger scope than the programmer intended (the entire remainder of the method, instead of only in the context of the try-catch-finally).  My question is, what were/are the rationale(s) behind this language design decision (in Java, in C#, and/or in any other applicable languages)?
57093
I think there's a lot for me to learn about data types. Why this happens  double result = ((3/8)*100).ToString();   it gives zero .. should be 37,5 ... :(
58615
Have you ever tried this before?  static void Main(string[] args) {     int x = 10;     x = x++;     Console.WriteLine(x); }   Output: 10.  but for   static void Main(string[] args) {     int x = 10;     x++;     Console.WriteLine(x); }   Output: 11.  Could anyone explain why this?
65906
Say I had;   \begin{equation}   \begin{cases}      x = 0 \\      y = 0 \\      z = 0     \end{cases}     \qquad \text{and} \qquad     \begin{cases}      x = a \\      y = a \\      z = b     \end{cases}   \end{equation}   How could I insert a brace ( } ) in the second 'cases' to say x and y are equal to a. (i.e. } = a ).   I hope this is clear, if not I can sketch it out - just let me know!  Thanks in advance!
92088
public class WrapperTest {      public static void main(String[] args) {          Integer i = 100;         Integer j = 100;          if(i == j)             System.out.println("same");         else             System.out.println("not same");     }     }   The above code gives the output of same when run, however if we change the value of i and j to 1000 the output changes to not same. As I'm preparing for SCJP, need to get the concept behind this clear. Can someone explain this behavior.Thanks.
69468
I solved this problem by manually adding parentheses and counting them, and got correct answer of 32. Is there a simple to find the answer? Thanks.     The value of the expression $1÷2÷3÷5÷7÷11÷13$ can be altered by including parentheses. If we are allowed to place as many parentheses as we want, how many distinct values can be obtained for this expression?
56680
I've seen both the blocks of code in use several different times, personally I have always used the first but my question is: is there a functional difference, and if there is what is it?  while (condition is true ) {     // do something }  do {     // do something } while ( condition is true);   I will be applying this to PHP but I assume this is fairly language agnostic.
103390
In a 2D game, I simply want to draw the trajectory of an arrow in flight. With the code below, the trajectory (the parabola) looks right, but the angle (or rotation) or the arrow isn't.   float g = -9.8f; float x = (launchVelocity * time); float y = (launchVelocity * time) + (0.5f * g * (float)Math.Pow(time, 2)); float angle = (float)Math.Tanh(y / x);   What am I missing? Thanks.
71596
expr does not seem to like parenthesis (used in mathematics to explicit operator priority):  expr 3 * (2 + 1) bash: syntax error near unexpected token `('   How to express operator priority in bash?
117123
I recently encountered a Stack Overflow question (since closed) in which the OP was testing for whether a triangle was right by whether or not it "met" the criteria of the Pythagorean Theorem (i.e. whether or not the square of the hypotenuse is equal to the square of the two sides). The code was to this effect:  public void Test(int a, int b, int c) {    if ((c * c) == ((a * a) + (b * b)) {      System.out.println("This is a right triangle");    }    else {      System.out.println("This is not a right triangle");    } }   (There are obviously some other problems with this code, like the fact that it doesn't validate the input to make sure that the inputs are positive and the fact that it only accepts integers).  The question was asking about something completely different in the code and never directly addressed the test, but I got to thinking: is this a valid test for whether a triangle is a right triangle?  Obviously, the Pythagorean Theorem states that, for all right triangles, $a^2 + b^2 = c^2$ (where $a$ and $b$ are sides and $c$ is the hypotenuse). This will hold for all right triangles, so being a right triangle is a sufficient condition for the Pythagorean Theorem to hold.  Is it also a necessary condition? I.e. if $c^2 = a^2 + b^2$ for some arbitrary triangle, is the triangle necessarily a right triangle? Or are there counterexamples?
13332
I am trying to use a  as input and then creating a query with it - so I need a .    I was surprised to find that it couldn't do the conversion implicitly or explicitly - but I don't even know how I would do this, as the Java API is still fairly new to me.
59699
Here is the code.  \documentclass{article} \begin{document} \directlua{tex.sprint(tostring(math.sin(math.pi)))} \\ \directlua{tex.sprint(tostring(math.tan(math.pi/2)))} \end{document}   I am expecting the answers as 0 and error . The code above gives some very small and big number. Can I get the expected answers by some modifications in code?