Is it possible to convert an `if` statement into a `switch` statement? [closed]

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Is it possible to convert an if statement into a switch statement in java?

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First of all, it's technically a switch block. Second of all, yes it is possible, but extremely unnecessary. However, if you want to do it, here is one way you could make the conversion...

int theCase;
if (someVariable.equals(someString)) {
    theCase = 1;
} else if (someVariable.equals(someOtherString)) {
    theCase = 2;
} else {
    theCase = 3;
}
switch (theCase) {
    case 1:
        //some code here
        break;
    case 2:
        //some code here
        break;
    case 3:
        //some code here
        break;
}

Of course, if you are comparing something other than strings you would use the == operator.

The two are also interchangeable, but only if you're working with chars or ints and only one condition is being tested.

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It depends on what is being evaluated in the if and how many of such related if statements you have.

If you have

if (i == 1)
{
    function1 (i)
}
else
if (i == 2)
{
    function2 (i)
}

if (i == 3)
{
    function3 (i)
}

then yes.

switch (i) {
    case 1:
        function1(i);
        break;
    case 2:
        function2(i);
        break;
    case 3:
        function3(i);
        break;
}

If you had multiple evaluations, then it becomes harder. if (i == 1) && (j == 2) will be much harder to represent in a switch-case block.

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I would not convert a single if statement into a switch statement, however it can be done. You will need to specify a default for the switch. If you are using many if...else statements that would warrant the switch.

int month = 8;
String monthString = "";
if(month == 1)
{
   monthString= "January";
}else if(month == 2)
{
  monthString= "February";
}else if(month== 3)
{
  monthString= "March";
}
etc....

Could be wrote like:

int month = 8;
String monthString;
switch (month) {
    case 1:  monthString = "January";       break;
    case 2:  monthString = "February";      break;
    case 3:  monthString = "March";         break;
    case 4:  monthString = "April";         break;
    case 5:  monthString = "May";           break;
    case 6:  monthString = "June";          break;
    case 7:  monthString = "July";          break;
    case 8:  monthString = "August";        break;
    case 9:  monthString = "September";     break;
    case 10: monthString = "October";       break;
    case 11: monthString = "November";      break;
    case 12: monthString = "December";      break;
    default: monthString = "Invalid month"; break;
}

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According to this example on oracles website, yes. Yes you can. Here's the link

http://download.oracle.com/javase/tutorial/java/nutsandbolts/switch.html

It just depends on how much typing you want to do. You can have a switch statement that only has one condition, or if statements that handle multiple conditions.

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In theory sure, but they are intended to check different things. An if statement is meant to respond to a particular boolean condition whereas a switch statement is meant to respond to a number of different possibilities. That said, you could easily rewrite a switch statement as a series of if else statements or vice versa. Typically though you really wouldn't want to do that. Use a hammer to drive nails and use a screw driver to drive screws. You could use either tool for either fastening device, they just don't work as well.