Question mark colon operator question

[orchid]

I inherited some code that I simply cannot sort out. Can anyone tell me why this prints off X88. It makes no sense to me.
Thanks

char x = 'X';
int i = 0;
System.out.print(true  ? x : 0);
System.out.print(false ? i : x);

[goldhouse]

This is an interesting operator in Java.

class TernaryOperator{

     public static void main(String[] args){
          int value1 = 1;
          int value2 = 2;
          int result;
          boolean someCondition = true;
          result = someCondition ? value1 : value2;
          System.out.println("First Result " +result);

          someCondition = false;
          result = someCondition ? value1 : value2;


          System.out.println("Second  Result " +result);

     }
}
Output:
First Result 1
Second Result 2

The code is self explanatory

[orchid]

It is not terribly readable. Why woulc anyone use it.

[goldhouse]

I forgot the answer the question ,BTW In java the expressions are evaluated from left to right
hence first one will evaluated as character
and second one will be an int type. The ascii value of 'X' is 88

Say what will happen


System.out.println( 2 + 2 + "2") // print 4
System.out.println( "" +2 + 2 ) // print 22

[miss.meli]

So this ? : operator is similar to an if else statement?

[dharmender378]

[QUOTE=goldhouse;285]I forgot the answer the question ,BTW In java the expressions are evaluated from left to right
hence first one will evaluated as character
and second one will be an int type. The ascii value of 'X' is 88

Say what will happen


System.out.println( 2 + 2 + "2") // print 4
System.out.println( "" +2 + 2 ) // print 22[/QUOTE
Ans:
System.out.println( 2 + 2 + "2") --------> Prints 42
System.out.println( "" +2 + 2 )----------->Prints 22

[dharmender378]

So this ? : operator is similar to an if else statement?

Yes, if the condition evaluates to be true then exp before the colon is executed otherwise the second exp post the colon is executed.

[Darryl.Burke]

> In java the expressions are evaluated from left to right
hence first one will evaluated as character
No.

The type returned by a ternary is the narrowest type that can accommodate both values. Try this code and clear up any misconception.

System.out.println(true ? 1.0 : 3);
System.out.println(true ? 1 : 3.0);

db

[Nicholas Jordan]

It is not terribly readable. Why woulc anyone use it.

Most people consider ternary operator to be difficult to read, we can expand thus wherever found:

( variable1.equals(variable2)? 5: 4  );

to

if(variable1.equals(variable2))return 5;
else return 4;

I use ternary operator once in maybe 500 lines of code, that's when I am in a mood to use it.

Especially challenging, if you want, is to code:

if(variable1.equals(variable2))
{
    if(variable2.equals(variable3))
    {
        System.out.println("proceed");
    }
    else
   {
       System.out.println("not available");
   }
}
else
{
     processData();
}

In ternary operators.

Looks convoluted in ternary operators, and is especially tangled to sort out when one does not have a great deal of code already written. What evenutally evolves is something called Trees, which remarkably can be written: ( ( ( ( ) ( ) ) ( ) )( ) )