HI,
Which is the correct way to get the value 开发者_如何学Gofrom a JComboBox as a String and why is it the correct way. Thanks.
String x = JComboBox.getSelectedItem().toString();
or
String x = (String)JComboBox.getSelectedItem();
If you have only put (non-null) String
references in the JComboBox, then either way is fine.
However, the first solution would also allow for future modifications in which you insert Integer
s, Doubles
s, LinkedList
s etc. as items in the combo box.
To be robust against null
values (still without casting) you may consider a third option:
String x = String.valueOf(JComboBox.getSelectedItem());
The first method is right.
The second method kills kittens if you attempt to do anything with x
after the fact other than Object
methods.
String x = JComboBox.getSelectedItem().toString();
will convert any value weather it is Integer, Double, Long, Short into text on the other hand,
String x = String.valueOf(JComboBox.getSelectedItem());
will avoid null values, and convert the selected item from object to string
Don't cast unless you must. There's nothign wrong with calling toString().
Note this isn't at heart a question about JComboBox, but about any collection that can include multiple types of objects. The same could be said for "How do I get a String out of a List?" or "How do I get a String
out of an Object[]
?"
JComboBox mycombo=new JComboBox(); //Creates mycombo JComboBox.
add(mycombo); //Adds it to the jframe.
mycombo.addItem("Hello Nepal"); //Adds data to the JComboBox.
String s=String.valueOf(mycombo.getSelectedItem()); //Assigns "Hello Nepal" to s.
System.out.println(s); //Prints "Hello Nepal".
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