Explain the concept of optionals in Swift.
Chapter20: Creating A Presentation
Section: Chapter Questions
Problem 2QY
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Transcribed Image Text:Explain the concept of optionals in Swift.
![What are the purpose and the output produced by the following code fragment?
a) Android
//public class databaseHelper
public Integer deleteRecord (String id) {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete("MyTable", "ID = ?",new String[] {id});
// MainActivity.java - method myMethod ()
databaseHelper myDB = new databaseHelper (this, null, null, 1);
EditText txtID = (EditText) findViewById(R.id.txtID);
Integer nRow = myDB.deleteRecord (txtID.getText().toString());
if (nRow > 0) {
Toast.makeText (MainActivity. this, "Success!", Toast.LENGTH_LONG).show();
} else {
Toast.makeText (MainActivity. this, "Error", Toast.LENGTH_LONG).show();
}](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fdfef1900-6b6b-4241-b7c7-4b23c6e468f2%2Fa01512be-f546-4cc8-b485-438eb4075332%2Ffl5htth_processed.png&w=3840&q=75)
Transcribed Image Text:What are the purpose and the output produced by the following code fragment?
a) Android
//public class databaseHelper
public Integer deleteRecord (String id) {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete("MyTable", "ID = ?",new String[] {id});
// MainActivity.java - method myMethod ()
databaseHelper myDB = new databaseHelper (this, null, null, 1);
EditText txtID = (EditText) findViewById(R.id.txtID);
Integer nRow = myDB.deleteRecord (txtID.getText().toString());
if (nRow > 0) {
Toast.makeText (MainActivity. this, "Success!", Toast.LENGTH_LONG).show();
} else {
Toast.makeText (MainActivity. this, "Error", Toast.LENGTH_LONG).show();
}
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