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Android The local variable tst may not have been initialized

My work code

@Override public boolean onMenuItemSelected(int featureId, MenuItem item) { Toast tst; if (item.getItemId() == R.id.menuVada) { tst = Toast.makeText(Main.this, " Vada ", 2000); } else { tst = Toast.makeText(Main.this, "Menu Title: " + item.getTitle() + " Menu ID: " + item.getItemId(), 2000); } tst.setGravity(Gravity.CENTER, 0, 0); tst.show(); return true; }

but this code does not work

 @Override public boolean onMenuItemSelected(int featureId, MenuItem item) { Toast tst; if (item.getItemId() == R.id.menuVada) { //tst = Toast.makeText(Main.this, " Vada ", 2000); } else { tst = Toast.makeText(Main.this, "Menu Title: " + item.getTitle() + " Menu ID: " + item.getItemId(), 2000); } tst.setGravity(Gravity.CENTER, 0, 0); tst.show(); return true; }

why doesn't my code work?

Please, help.

Best wishes

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7 answers

What if (item.getItemId() == R.id.menuVada) ?

just initialize tst to null . And then check if tst!=null shows a toast

 @Override public boolean onMenuItemSelected(int featureId, MenuItem item) { Toast tst = null; if (item.getItemId() == R.id.menuVada) { //tst = Toast.makeText(Main.this, " Vada ", 2000); } else { tst = Toast.makeText(Main.this, "Menu Title: " + item.getTitle() + " Menu ID: " + item.getItemId(), 2000); } if(tst!=null){ tst.setGravity(Gravity.CENTER, 0, 0); tst.show(); } return true; }
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Your variable Toast tst; must be initialized as in if and else .

becasue, if you find your if() condition is true , then the else part will never be called. and the application thread will move on to the next and throw a NullPointerException

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Yes, in the if tst branch is not initialized. But if you show Toast in only one branch, I would include the declaration, gravity and show the lines in this branch.

 @Override public boolean onMenuItemSelected(int featureId, MenuItem item) { if (item.getItemId() == R.id.menuVada) { } else { Toast tst = Toast.makeText(Main.this, "Menu Title: " + item.getTitle() + " Menu ID: " + item.getItemId(), 2000); tst.setGravity(Gravity.CENTER, 0, 0); tst.show(); } return true; }

Otherwise use Serif.

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You must initialize the variable before using it. Try the following:

 Toast tst = null;

But you will get a null-reference exception if the code does not accept the else branch. So, in a sense, you can still say that the code is not working ... It just compiles.

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Because if your test if() is true, it will go to the empty branch, where the purpose of tst commented out. tst therefore not initialized when you go to tst.setGravity() .

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I think you should make it static. Like

 Static tst;

Or do this to save tst in another variable, then attach your Toast class as

 Toast t = new Toast(); t.tst = // your variable

Hope it works

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You can just try:

 @Override public boolean onMenuItemSelected(int featureId, MenuItem item) { if (item.getItemId() == R.id.menuVada) { Toast.makeText(Main.this, " Vada ", 2000); } else { Toast.makeText(Main.this, "Menu Title: " + item.getTitle() + " Menu ID: " + item.getItemId(), 2000); } return true; }

EDIT to comment.

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