How can I reduce if-else statements

Question

My code:

if(!"".equals(et1.getText().toString())){
   Toast.makeText(getActivity(), "Please enter text1", Toast.LENGTH_SHORT).show();
} else if(!"".equals(et2.getText().toString())){
   Toast.makeText(getActivity(), "Please enter text2", Toast.LENGTH_SHORT).show();
} else if(!"".equals(et3.getText().toString())){
   Toast.makeText(getActivity(), "Please enter text3", Toast.LENGTH_SHORT).show();
} else if(!"".equals(et4.getText().toString())){
   Toast.makeText(getActivity(), "Please enter text4", Toast.LENGTH_SHORT).show();
} else if(!"".equals(et5.getText().toString())){
   Toast.makeText(getActivity(), "Please enter text5", Toast.LENGTH_SHORT).show();
}

//Totally 13 fields, so this will go near 13 checking. So just I want to know is there any possibility to check with one statement and find which filed is leaved as empty.

Thank you.

I think instead of showing different Toast messages for all fields you can just use a single message. Like "Please fill all fields." Then you can write the condition in one line using && operator. — arshu, Oct 24 '13 at 06:11
id advice you put a star against each field that is necessary, compare all the values inside one if statement using || and then display a common message! — Rat-a-tat-a-tat Ratatouille, Oct 24 '13 at 06:12

score 5 · Answer 1 · answered Oct 24 '13 at 06:12

5

Store the objects (et1, 2, 3, ...) in an array, and then iterate on it.

answered Oct 24 '13 at 06:12

Antzi

12,831
7
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While it works, i think it is against the OOP approach. When you need to use many `if` statements like OP, then consider polymorphism to solve the task. – Oct 24 '13 at 06:14
I just want to check within one execution, Anyway thanks for your help. +1 added. – Gunaseelan Oct 24 '13 at 07:12

score 1 · Answer 2 · edited Dec 24 '15 at 15:10

You can Add a textwatcher to your fields. see the snippet below.

private class GenericTextWatcher implements TextWatcher {

    private GenericTextWatcher() {

    }

    public void afterTextChanged(Editable editable) {

       if(editable.toString().equals(""))
       {
           Toast.makeText(UrActivity.this, "ur toast", Toast.LENGTH_LONG).show();
       }
    }

    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
    }

    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
    }
}

and then register textlistener.

editext.addTextChangedListener(new GenericTextWatcher());

validating it on actual keypress will be faster then clubbing the checking later.

I just want to check within one execution for all `EditText`, Anyway thanks for your help. +1 added. — Gunaseelan, Oct 24 '13 at 07:13

score 1 · Accepted Answer · answered Oct 24 '13 at 06:21

1

store it in a List

for (EditText et : etList) {
    if(!"".equals(et.getText().toString()))
}

answered Oct 24 '13 at 06:21

chip

1,779
1
22
34

I didn't ask this type of answer, But this one reduce my code length. Thank you. – Gunaseelan Oct 24 '13 at 07:08

score 0 · Answer 4 · 2013-10-24T08:40:41.897

I would implement view classes (in Model-View-Controller notation) that represent the necessary controls and would use polymorphism to avoid these if statements.

UPDATE:

As I understand there is shown an input validation mechanism. I would do the following.

My explanation could be more general than it is expected for your particular task. But I think it will help you in future. And please note I am not too proficient with Android API, so you may need to adjuct my references to some Android API classes, for instance a class, that represents a field.

So, the first step. Declare the field prototype:

abstract FieldPrototype extends AndroidFieldClass {

    /**
    * Checks field contents and returns true if field is ok, otherwise shows popup validation message and returns false.
    * @return see method description.
    */
    public abstract boolean checkField();

}


class Et1Field extends FieldPrototype {

    private String value;

    public Et1Field() {
        super();
        // your initialization code here
    }

    public boolean checkField() {
        if (value == null || "".equals(value)) {
            // show validation message specific for Et1Field class instance.
            return false;
        }

        return true;
    }
}

// do the same steps for Et2Field .. Et13Field if those fields are different, 
// and implement specific validation functionality for every kind of a field.

In your screen class keep an array of all fields displayed on this screen. On save event in your screen, send save event to all field instances. Every field will invoke it's own checkField() method and validate it's own contents, without showing particular field implementation outside. And if a field validation failed you just stop and let a user to correct a field contents.

Can you elaborate more please, Because I didn't get you. – Gunaseelan Oct 24 '13 at 07:14 — Gunaseelan, Oct 24 '13 at 07:14
@Gunaseelan I have added an update, please check it. – Oct 24 '13 at 08:41 — , Oct 24 '13 at 08:41

score 0 · Answer 5 · answered Oct 24 '13 at 06:24

0

make one function to check blank and called it once like this...

    checkBlank(et1.getText().toString()), 1);
checkBlank(et2.getText().toString()), 2);
checkBlank(et3.getText().toString()), 3);..and so on

here is function..

private void checkBlank(String edt,int pos) {
    // TODO Auto-generated method stub
    if(edt.equals(""))
    {
        Toast.makeText(getApplicationContext(), "Please enter text"+pos, Toast.LENGTH_SHORT).show();
    }

}

Godd Luck:)

answered Oct 24 '13 at 06:24

Kalpesh Lakhani

1,003
14
28

1

your code and posted question is executes as same you are just written in one method no more change.. – kalyan pvs Oct 24 '13 at 06:27

How can I reduce if-else statements

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