The expression is not parsed the way you think. It&#39;s not

    (test1=false) || (test1 == false)

in which case the result would have been `true`, but

    test1 = (false || test1 == false)

The value of `false || test1 == false` expression is computed first, and it is `false`, because `test1` is set to `true` going into the computation.

The reason it is parsed this way is that the [precedence][1] of the `||` is lower than that of the `==` operator, but higher than the precedence of the assignment operator `=`.

  [1]: http://introcs.cs.princeton.edu/java/11precedence/

This is a precedence issue, basically. You&#39;re assuming that your code is equivalent to:

    if ((test1 = false) || (test1 == false))

... but it&#39;s not. It&#39;s actually equivalent to:

    if (test1 = (false || test1 == false))

... which is equivalent to:

    if (test1 = (false || false))

(because `test1` is `true` to start with)

... which is equivalent to:

    if (test1 = false)

which assigns the value `false` to `test1`, with the result of the expression being `false`.

See the [Java tutorial on operators][1] for a useful table of operator precedence.


  [1]: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/operators.html

![please have a look over precedence of operators][1]


  [1]: http://i.stack.imgur.com/UcG6x.gif


Expression `test1 = false || test1 == false` will evaluate in following step.

**STEP:1-** `test1 = false || test1 == false` //precedence of `==` is highest

**STEP:2-** `test1 = false || false`// Operator `||` have higher precedence

**STEP:3-** `test1 = false `

**STEP:4-** `false`

Since boolean value of expression becomes false.So else statement is being executed.


`(test1 = false || test1 == false)` returns false, because both of them are false.`(test1 = false || test1 == true)` this is true because one of them is true

Why are objects not iterable by default?

**I see questions all the time related to iterating objects, the common solution being to iterate over an object&#39;s properties and accessing the values within an object that way. This seems so common that it makes me wonder why objects themselves aren&#39;t iterable.**

Statements like the ES6 [`for...of`][1] would be nice to use for objects by default. Because these features are only available for special &quot;iterable objects&quot; which don&#39;t include `{}` objects, we have to go through hoops to make this work for objects we want to use it for. 

&gt; The for...of statement creates a loop Iterating over **iterable objects**
&gt; (including Array, Map, Set, arguments object and so on)...

For example using an ES6 [generator function][2]:

    var example = {a: {e: &#39;one&#39;, f: &#39;two&#39;}, b: {g: &#39;three&#39;}, c: {h: &#39;four&#39;, i: &#39;five&#39;}};
    
    function* entries(obj) {
       for (let key of Object.keys(obj)) {
         yield [key, obj[key]];
       }
    }
    
    for (let [key, value] of entries(example)) {
      console.log(key);
      console.log(value);
      for (let [key, value] of entries(value)) {
        console.log(key);
        console.log(value);
      }
    }

The above properly logs data in the order I expect it to when I run the code in Firefox (which supports [ES6][3]):

![output of hacky for...of][4]

**By default, `{}` objects are not iterable, but why? Would the disadvantages outweigh the potential benefits of objects being iterable? What are the issues associated with this?**

In addition, because `{}` objects are different from &quot;Array-like&quot; collections and &quot;iterable objects&quot; such as [`NodeList`][7], [`HtmlCollection`][8], and [`arguments`][9], they can&#39;t be converted into Arrays.

For example:

`var argumentsArray = Array.prototype.slice.call(arguments);` 

or be used with Array methods:

`Array.prototype.forEach.call(nodeList, function (element) {})`.

**Besides the questions I have above, I would love to see a working example on how to make `{}` objects into iterables, especially from those who have mentioned the `[Symbol.iterator]`.** This should allow these new `{}` &quot;iterable objects&quot; to use statements like `for...of`. Also, I wonder if making objects iterable allow them to be converted into Arrays.

I tried the below code, but I get a `TypeError: can&#39;t convert undefined to object`.

    var example = {a: {e: &#39;one&#39;, f: &#39;two&#39;}, b: {g: &#39;three&#39;}, c: {h: &#39;four&#39;, i: &#39;five&#39;}};
    
    // I want to be able to use &quot;for...of&quot; for the &quot;example&quot; object.
    // I also want to be able to convert the &quot;example&quot; object into an Array.
    example[Symbol.iterator] = function* (obj) {
       for (let key of Object.keys(obj)) {
         yield [key, obj[key]];
       }
    };
    
    for (let [key, value] of example) { console.log(value); } // error
    console.log([...example]); // error


  [1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of
  [2]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*
  [3]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/New_in_JavaScript/ECMAScript_6_support_in_Mozilla
  [4]: http://i.stack.imgur.com/SSJbr.png
  [5]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in
  [6]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for
  [7]: https://developer.mozilla.org/en-US/docs/Web/API/NodeList
  [8]: https://developer.mozilla.org/en-US/docs/Web/API/HTMLCollection
  [9]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments
  [10]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols

Why are Objects not Iterable in JavaScript?

i have used Xampp and JetBrain WebStorm to run an AngularJS project. But it&#39;s complicated and low performance.Is there any other way to run an AngularJS project?

How to create a localhost server to run an AngularJS project

How does a Java *if statement* work when it has an assignment and an equality check `OR`-d together??

    public static void test() {
        boolean test1 = true; 
    	if (test1 = false || test1 == false) {
    		System.out.println(&quot;TRUE&quot;);
    	} else {
    		System.out.println(&quot;FALSE&quot;);
    	}		
    }

Why is this printing FALSE?

Why does this if statement, with an assignment and equality check, evaluate to false?

How does a Java if statement work when it has an assignment and an equality check <code>OR</code>-d together??
<pre><code class="hljs language-csharp">public static void test() {
 boolean test1 = true; 
	if (test1 = false || test1 == false) {
		System.out.println("TRUE");
	} else {
		System.out.println("FALSE");
	}		
}
</code></pre>
Why is this printing FALSE?

Code:-

    try {
        Assert.assertEquals(&quot;1&quot;, &quot;2&quot;);
    } catch (Exception e) {
        System.out.println(&quot;I am in error block&quot;);
    }

If the assert statements fails, I would like to capture the error in the catch block. I am trying with the above code and its not happening.

Will the assertion error be caught by in a catch block for java exception? 


Will an assertion error be caught by in a catch block for java exception?

Given a list of cars (`List&lt;Car&gt; cars`), I can do:

    Observable.just(cars); //returns an Observable that emits one List&lt;Car&gt;
    Observable.from(cars); //returns an Observable that emits a squence of Car

Is there a way I can go from an `Observable` of a `List&lt;Car&gt;` to a sequence of `Observable&lt;Car&gt;`?

Something like a `from` without parameters

    Obserable.just(cars).from()

Convert Observable&lt;List&lt;Car&gt;&gt; to a sequence of Observable&lt;Car&gt; in RxJava

AdminTokenAction: FATAL ERROR: Cannot obtain Application SSO token

Someone explain to me the differences between the following two statements?

A `static final` variable initialized by a `static` code block:

    private static final String foo;
    static { foo = &quot;foo&quot;; }

A `static final` variable initialized by an assignment:

    private static final String foo = &quot;foo&quot;;

Difference between static modifier and static block

While running 

    sencha app build production
I am getting the following error:

&gt; Error: Registry key &#39;Software\JavaSoft\Java Runtime
&gt; Environment&#39;\CurrentVersion&#39;
&gt; 
&gt; has value &#39;1.8&#39;, but &#39;1.7&#39; is required. Error: could not find java.dll
&gt; Error: Could not find Java SE Runtime Environment.

 `java -version` , command is showing following:

java version &quot;1.8.0_40&quot;
Java(TM) SE Runtime Environment (build 1.8.0_40-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

Not able to find where path is going wrong. Any idea?

----------------------- EDIT ------------------------------------------------

**Note**: I am using Windows 7 (64 bit). 

I have tried uninstalling the sencha touch cmd and reinstalling. But still same error.

I have uninstalled all the java version instances and reinstalled the latest one, Still the problem persist.

Registry key Error: Java version has value &#39;1.8&#39;, but &#39;1.7&#39; is required

What is the difference between these two lines of code:

    if not x == &#39;val&#39;:
and 

    if x != &#39;val&#39;:


Is one more efficient than the other?


Would it be better to use

    if x == &#39;val&#39;:
        pass
    else:


Python if not == vs if !=

I&#39;ve found this string in JavaScript code.

    var c = (a.b !== null) ? a.b : null;

This is a shorthand of an if-else statement, however the value null is assigned if it is null. Isn&#39;t that **ALWAYS** equivalent to

    var c = a.b

including all cases - exceptions, null, undefined, etc?

In another words, are these lines (always) equivalent?

    var c = (a.b !== null) ? a.b : null;

-vs-

    var c = a.b

Are these lines of JavaScript code equivalent?

I was reading Java&#39;s `ArrayList` source code and noticed some comparisons in if-statements.

In Java 7, the method [`grow(int)`](http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/7-b147/java/util/ArrayList.java#ArrayList.grow%28int%29) uses

    if (newCapacity - minCapacity &lt; 0)
        newCapacity = minCapacity;

In Java 6, `grow` didn&#39;t exist. The method [`ensureCapacity(int)`](http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b27/java/util/ArrayList.java#ArrayList.ensureCapacity%28int%29) however uses

    if (newCapacity &lt; minCapacity)
        newCapacity = minCapacity;

What was the reason behind the change? Was it a performance issue or just a style? 

I could imagine that comparing against zero is faster, but performing a complete subtraction just to check whether it&#39;s negative seems a bit overkill to me. Also in terms of bytecode, this would involve two instructions (`ISUB` and `IF_ICMPGE`) instead of one (`IFGE`).

Difference between if (a - b &lt; 0) and if (a &lt; b)

We can write an `if` statement as

    if (a == 5, b == 6, ... , thisMustBeTrue)

and only the last condition should be satisfiable to enter the `if` body.

why is it allowed?


What is the advantage of commas in a conditional statement?

If I try to compile 

    for(;;)
    {
            
    }
    System.out.println(&quot;End&quot;);

The Java compiler produces an error saying `Unreachable statement`. But if I add another &quot;*unreachable*&quot;(according to me) `break` statement and make it: 

    for(;;)
    {
        if(false) break;
    }
    System.out.println(&quot;End&quot;);

It compiles. Why does it not produce an error?

Why does a Java Compiler not produce an unreachable statement error for an unreachable then statement?

The logical expression `( a &amp;&amp; b )` *(both `a` and `b` have boolean values)* can be written like `!(!a || !b)`, for example. Doesn&#39;t this mean that `&amp;&amp;` is &quot;unneccesary&quot;? Does this mean that *all* logical expressions can be made only using `||` and `!`? 

Are || and ! operators sufficient to make every possible logical expression?

I was browsing some C++ code, and found something like this:

    (a + (b &amp; 255)) &amp; 255

The double AND annoyed me, so I thought of:

    (a + b) &amp; 255

(`a` and `b` are 32-bit unsigned integers)

I quickly wrote a test script (JS) to confirm my theory:

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    for (var i = 0; i &lt; 100; i++) {
        var a = Math.ceil(Math.random() * 0xFFFF),
            b = Math.ceil(Math.random() * 0xFFFF);

        var expr1 = (a + (b &amp; 255)) &amp; 255,
            expr2 = (a + b) &amp; 255;

        if (expr1 != expr2) {
            console.log(&quot;Numbers &quot; + a + &quot; and &quot; + b + &quot; mismatch!&quot;);
            break;
        }
    }

&lt;!-- end snippet --&gt;

While the script confirmed my hypothesis (both operations are equal), I still don&#39;t trust it, because 1) [random](https://xkcd.com/221/) and 2) I&#39;m not a mathematician, [I have no idea what am I doing](http://i.imgur.com/Boq967h.png).

Also, sorry for the Lisp-y title. Feel free to edit it.

Content Type	Original Author	Original Content on Stackoverflow
Question	RoHaN	View Question on Stackoverflow
Solution 1 - Java	Sergey Kalinichenko	View Answer on Stackoverflow
Solution 2 - Java	Jon Skeet	View Answer on Stackoverflow
Solution 3 - Java	user4768611	View Answer on Stackoverflow
Solution 4 - Java	Den	View Answer on Stackoverflow

Why does this if statement, with an assignment and equality check, evaluate to false?

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Why are Objects not Iterable in JavaScript?

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