Question

Is there a difference between these ?

if(myString.equals("")){

}

if(myString.equals(null)){

}

if(myString == ""){

}

I have a string, I don’t know is it empty or has some emtpy spaces I just wan’t to stop it to be written in database if it is invalid(if empty or with some blank spaces).

Answer 1

To achieve what you want, write:

if (!myString.trim().equals("")) {
    // write to database
}

or if there is also a possibility that myString may be null:

if (myString != null && !myString.trim().equals("")) {
    // write to database
}