How can I check the below conditions in switch instead of if?

Question

I want to check this conditions in switch case.

if(tvStartLocation.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter start location", Toast.LENGTH_SHORT).show();
}
else if(tvEndLocation.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter end location", Toast.LENGTH_SHORT).show();
}
else if(etStartOdometer.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter Trip Start Odometer reading", Toast.LENGTH_SHORT).show();
}
else if(etEndOdometer.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter Trip End Odometer reading", Toast.LENGTH_SHORT).show();
}
else if((compareOdometerReading(etStartOdometer.getText().toString(),etEndOdometer.getText().toString())) == -1)
{
    Toast.makeText(getActivity(),"End Odometer reading should be greater than Start Odometer Reading (eOR > sOR)!", Toast.LENGTH_SHORT).show();
}
else if(etManifest.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter Manifest", Toast.LENGTH_SHORT).show();
}
else if(etShipper.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter Shipper", Toast.LENGTH_SHORT).show();
}
else if(etCommodity.getText().toString().equalsIgnoreCase(""))
{
    Toast.makeText(getActivity(),"Please enter Commodity", Toast.LENGTH_SHORT).show();
}

Suggest Me Guys In Advance

You can't. You are comparing a bunch of different variables to one constant. Switches are for comparing one variable to a bunch of constants. You could, however simplify your `if` conditions to `...getText().isEmpty()`, assuming `getText()` returns a `String` anyway. — khelwood, Feb 09 '15 at 11:43
You need Java 1.7 for that! Still your use case will not allow to use the same! TO reduce your if else chain I recommend that you go through [this](http://stackoverflow.com/questions/7349883/how-to-remove-large-if-else-if-chain) — Skynet, Feb 09 '15 at 11:44

score 2 · Answer 1 · answered Feb 09 '15 at 11:43

2

In a switch statement you compare one variable against different constant values. You want to compare different variables against one constant value. This is not possible, and IMHO, does not make sense in your case.

answered Feb 09 '15 at 11:43

Thomas Stets

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Java 1.7 makes it possible to use switch on Strings. – Skynet Feb 09 '15 at 11:44
@Skynet Only if the cases are *constant* strings. – khelwood Feb 09 '15 at 11:46
Yes, against String constants. He only has one String constant: "", but a list of different variables he wants to check. – Thomas Stets Feb 09 '15 at 11:46
@khelwood I second you :) Also noteworthy is that ANdroid as of now only supports Java 1.5 and 1.6. I would also second using isEmpty() as suggested by you. – Skynet Feb 09 '15 at 11:47

score 0 · Answer 2 · answered Feb 09 '15 at 11:50

As others mentioned you are comparing multiple variables to a constant, and switch cannot do that. But you could improve code reuse and readability by putting all those variables in array or list and then iterating over them. For example something like this:

TextView[] toValidate = new TextView[]{tvStartLocation, tvEndLocation, etStartOdometer}; //etc

for(TextView tv : toValidate){
     if(tv.getText().toString().equalsIgnoreCase(""))
     {
          //Display message.. 
     }
}

score 0 · Answer 3 · answered Feb 09 '15 at 11:50

You can't replace them with a switch statement, since each condition checks a different variable. You could replace them with a method, to avoid code duplication.

public boolean testControl (EditText control, String name) { // I'm assuming your control is an EditText 
                                              // (perhaps I got the type wrong)
    if (control.getText().toString().equalsIgnoreCase("")) {
        Toast.makeText(getActivity(),"Please enter " + name, Toast.LENGTH_SHORT).show();
        return false;
    }
    return true;
}

You can call the method :

boolean hasValue = testControl (etShipper, "Shipper");

Then, if you store your EditText controls in some array/Collection, you can call this method in a loop.

How can I check the below conditions in switch instead of if?

3 Answers3