blocks|key|561879|text|Tadaaaa：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|561880|public+static+void+main(String+args[])+{++++
++++if(!new+Object()+{
++++++++public+boolean+foo()+{
++++++++++++System.out.print("Hello+");
++++++++++++return+true;
++++++++}
++++}.foo()){
++++++++System.out.println("Hello");
++++}else{
++++++++System.out.println("World");
++++}
}|code-block|syntax|javascript|561881|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Tadaaaa:

<pre><code>public static void main(String args[]) { 
 if(!new Object() {
 public boolean foo() {
 System.out.print("Hello ");
 return true;
 }
 }.foo()){
 System.out.println("Hello");
 }else{
 System.out.println("World");
 }
}
</code></pre>

blocks|key|561920|text|我可以提供|type|unstyled|depth|inlineStyleRanges|entityRanges|data|561921|if+(System.out.printf("%25s","Hello+")+==+null)+{
++++System.out.println("Hello");
}+else+{
++++System.out.println("World");
}|code-block|syntax|javascript|561922|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I can offer

<pre><code>if (System.out.printf("%s","Hello ") == null) {
 System.out.println("Hello");
} else {
 System.out.println("World");
}
</code></pre>

blocks|key|561828|text|它不起作用，因为在Java语言中，if需要一个boolean类型的表达式。System.out.println没有返回类型，它是void。这就是它不起作用的原因。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|561829|entityMap^0|H|2|N|7|11|I|1S|4|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|G|$]]

It doesn't work because in Java <code>if</code> expects an expression of type <code>boolean</code>. <code>System.out.println</code> has no return type, it is <code>void</code>. That's why it doesn't work.

blocks|key|562012|text|public+class+HelloWorld{
++++public+static+void+main(String[]args){
++++++++if+(new+Object(){{+System.out.print("Hello+");+}}+==+null){
++++++++++++System.out.println("Hello");
++++++++}else{
++++++++++++System.out.println("World");
++++++++}
++++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|562013|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>public class HelloWorld{
 public static void main(String[]args){
 if (new Object(){{ System.out.print("Hello "); }} == null){
 System.out.println("Hello");
 }else{
 System.out.println("World");
 }
 }
}
</code></pre>

blocks|key|346042|text|打开args的内容，并使用两个不同的参数运行该程序两次。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|346043|除非您除了修复if()结构之外还修改了println的输入，否则您的程序将输出"Hello“或"World”。|346044|entityMap^0|2|4|0|7|4|J|7|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|R|8|@]|D|@]|E|$]]]|I|$]]

Switch on the contents of <code>args</code> and run the program twice with two different parameters.

Your program will either print out "Hello" or "World" unless you modify the input to <code>println</code> in addition to fixing your <code>if()</code> construct.

blocks|key|346277|text|考虑下面的代码来执行C语言中的if-else块语句。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|346278|#include+<stdio.h>
#include+<stdbool.h>
int+main()
{

++bool+flag+=+false;
++if(flag)
++{
++++printf("if+block+returns+true->+now+redirecting+to+else");
++++goto+el;
++++i:
++++printf("+redirected+to+if");
++}
++else
++{
++++printf("if+block+returns+false->+now+redirecting+to+if");
++++goto+i;
++++el:
++++printf("+redirected+to+else");
++}
}|code-block|syntax|javascript|346279|只需更改上面代码中的标志值。例如，如果标志值更改为true，则首先执行if块，然后执行else。|346280|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Consider the below code to execute both if-else block statements in C.
<pre><code>#include &lt;stdio.h&gt;
#include &lt;stdbool.h&gt;
int main()
{

 bool flag = false;
 if(flag)
 {
 printf(&quot;if block returns true-&gt; now redirecting to else&quot;);
 goto el;
 i:
 printf(&quot; redirected to if&quot;);
 }
 else
 {
 printf(&quot;if block returns false-&gt; now redirecting to if&quot;);
 goto i;
 el:
 printf(&quot; redirected to else&quot;);
 }
}
</code></pre>
Just change the flag value in the above code.
For example, if the flag value changed to true then first if block will execute and then else.

blocks|key|562001|text|您可以使用append而不是println来确定写入是否成功：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|562002|if+(System.out.append("Hello+World"+%2B+System.getProperty("line.separator"))+!=+null)
{
++++//+some+code+here
}|code-block|syntax|javascript|562003|entityMap^0|5|6|E|7|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

You could use <code>append</code> instead of <code>println</code> to determine if the write was successful:

<pre><code>if (System.out.append("Hello World" + System.getProperty("line.separator")) != null)
{
 // some code here
}
</code></pre>

blocks|key|346116|text|这也可以在不指定格式的情况下使用"printf“实现。代码如下：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|346117|if+(System.out.printf("Hello")+==+null)+{
++++System.out.print("Hello");
}+else+{
++++System.out.println("World");
}|code-block|syntax|javascript|346118|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This can also be achieved using "printf" with out specifying the format. the code goes as below:

<pre><code>if (System.out.printf("Hello") == null) {
 System.out.print("Hello");
} else {
 System.out.println("World");
}
</code></pre>

blocks|key|346146|text|看看这个。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|346147|class+Test+{

++++static+boolean+x+=+true;

++++public+static+void+main(String[]+args)+{
++++++++ifAndElse();

++++}

++++public+static+void+ifAndElse(){
++++++++if+(x)+{
++++++++++++System.out.println("hi");
++++++++++++x+=+false;
++++++++++++ifAndElse();
++++++++}+else+{
++++++++++++System.out.println("hello");
++++++++}
++++}
}|code-block|syntax|javascript|346148|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Check this one...

<pre><code>class Test {

 static boolean x = true;

 public static void main(String[] args) {
 ifAndElse();

 }

 public static void ifAndElse(){
 if (x) {
 System.out.println("hi");
 x = false;
 ifAndElse();
 } else {
 System.out.println("hello");
 }
 }
}
</code></pre>

blocks|key|562107|text|**+Try+this+one+**
class+Test
{
++++public+static+void+main(String+args[])
++++{
++++++++boolean+one=true;
++++++++for(int+i=0;i<2;i%2B%2B)
++++++++{
++++++++if(one)
++++++++{
++++++++++++System.out.print("Hello");
++++++++++++one=false;++
++++++++}+++
++++++++else

++++++++++++System.out.println("World!");

++++++++}+++++++
++++}
}`|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|562108|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>** Try this one **
class Test
{
 public static void main(String args[])
 {
 boolean one=true;
 for(int i=0;i&lt;2;i++)
 {
 if(one)
 {
 System.out.print("Hello");
 one=false; 
 } 
 else

 System.out.println("World!");

 } 
 }
}`
</code></pre>

blocks|key|562154|text|public+class+Test+{++

+++++++public+static+void+main(String+args[])+{++

++++++++++++if+(args==null+%7C%7C+new+Test()+{{Test.main(null);}}.equals(null))+{++
+++++++++++++++++++++System.out.print("Hello+");
++++++++++++}+else+{++
+++++++++++++++++++++System.out.print("World！");++
++++++++++++}++
+++++++}++
}++|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|562155|这是可行的，但是理解起来有点复杂。|unstyled|562156|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>public class Test { 

 public static void main(String args[]) { 

 if (args==null || new Test() {{Test.main(null);}}.equals(null)) { 
 System.out.print("Hello ");
 } else { 
 System.out.print("World！"); 
 } 
 } 
} 
</code></pre>

this can work, but a little bit complicate for understanding

Interesting problem:

Change if statement and print out "Hello World" 

<pre><code> public static void main(String[] args) {
 if(){
 System.out.println("Hello");
 }else{
 System.out.println("World");
 }
 }
</code></pre>

My solution is to add "!System.out.println("Hello")" 
in the if statement,But it doesn't work, any ideas?

<pre><code> public static void main(String[] args) {
 if(!System.out.println("Hello")){
 System.out.println("Hello");
 }else{
 System.out.println("World");
 }
 }
</code></pre>

UPDATE:
I think this works:

<pre><code> public static void main(String args[]) { 
 if(System.out.append("Hello ")==null){
 System.out.print("Hello ");
 }else{
 System.out.println("World");
 } 
 }
</code></pre>

In C:

<pre><code>main()
{ if(printf("Hello"),0)
 printf("Hello");
 else
 printf(" world!\n");
 getch();
}
</code></pre>

How to execute the "if" and "else" at the same time?

Java

有趣的问题：更改if语句并输出"Hello World“    public static void main(String[] args) {        if(){            System.out.println("Hello");        }else{            System.out.println("World");        }    }我的解决方案是

问如何同时执行if和else？
EN

回答 11

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问如何同时执行if和else？EN

回答 11

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问如何同时执行if和else？
EN