Safeguard a String from being null in JTextfield using if-else

Question

I'm a novice in Java. I want to remind my user if they didn't enter a String in the JTextField, so I use an if-else statement to safeguard. However, the reminder doesn't jump out when I test it.

How do I safeguard a string from being null in text field using if-else statement?

if ( !name == null && score >= 0) {
    Student stu = new Student(name, score);
    students.add(stu);
    }
}
else if(name == null) {
    reminder.setText("Could you tell me your name?");
}
else{
    reminder.setText("Enter numbers for score! Must be a positive number!");
}

the braces/formatting don't make sense. separately, checking if `name` is null would not catch an empty value – that is, `name` might contain an empty string `""`. — Kaan, Dec 19 '19 at 20:28
Please clarify: what is the context, framework you using, how you get the name, type of reminder etc. Also will be much nicer if you format the code properly. — Oleg Imanilov, Dec 19 '19 at 20:36

score 2 · Answer 1 · answered Dec 19 '19 at 20:52

2

Null checks are if (object != null) and if you want to check if a text field is filled,

JTextField field = new JTextField();
String text = field.getText();
if (text != null && text.length() > 0) {
    System.out.println("Field has data");
}

answered Dec 19 '19 at 20:52

Joe

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Safeguard a String from being null in JTextfield using if-else

1 Answers1