If statement is ignored

Question

I am making a simple matchmaker as a learning project in JAVA. My program so far just asks a few questions, but I wanted to do gender specific questions, so I asked for their sex (m or f) and then attempted to add a message that only showed if sex was m. The dialog should say "well done, you are male!". Else it restarts method. Every time, no matter what I type it restarts the program.

Here is my code:

import javax.swing.JOptionPane;

public class Main {

    public static void main(String[] args){
        setVars();
    }

    public static void setVars(){
        String name = JOptionPane.showInputDialog(null, "What is your name?");
        String sAge = JOptionPane.showInputDialog(null, "What is your age?");
        String sex = JOptionPane.showInputDialog(null, "What is your sex?\n(Enter  m or f)");

        if (sex == "m"){
            JOptionPane.showMessageDialog(null, "Well done, you are male.\nKeep Going!");
        }
        int age = Integer.parseInt(sAge);
        String chars = JOptionPane.showInputDialog(null, "Name three charectaristics");
    }
}

`"m"` is _not_ the same as `sex`, even if the value of `sex` is `"m"`. String comparisons should be done using `equals()` (as mentioned above), which compares the equalness, not the identity. — thriqon, Oct 19 '13 at 16:04

score 1 · Answer 1 · answered Oct 19 '13 at 15:44

1

try

if ( "m".equalIgnoreCase(sex))

you should use equals for comparing string value and == for checking their references

answered Oct 19 '13 at 15:44

upog

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zmirc · Answer 2 · 2013-10-19T16:42:21.100

1

Your code should be:

if ("m".equals(sex)) {
  //
}

== compares objects' addresses / references
.equals compares objects' values

edited Oct 19 '13 at 16:42

answered Oct 19 '13 at 15:44

zmirc

825
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1

It should be `"m".equals(sex)` because `sex` is possible to be `null` – Tuna Oct 19 '13 at 16:05

score 1 · Answer 3 · answered Oct 19 '13 at 15:44

In Java, you dont' compare strings with ==, you have to compare them with the equals() method on String. String has two variants of this method: equals() which is case sensitive, and equalsIgnoreCase(), which is case insensitive. In the examples below, you can use either one.

Try this:

if(sex.equalsIgnoreCase("m") {
    ...
}

Or to guard against nulls...

if("m".equalsIgnoreCase(sex)) {
    ...
}

score 0 · Answer 4 · answered Oct 19 '13 at 15:54

because String is an object not a data type like int when it comes to compare two Strings it is done by .equals() method:

package example;

import javax.swing.JOptionPane;
public class Main {
    public static void main(String[] args){
        setVars();
    }
    public static void setVars(){
        String name = JOptionPane.showInputDialog(null, "What is your name?");
        String sAge = JOptionPane.showInputDialog(null, "What is your age?");
        String sex = JOptionPane.showInputDialog(null, "What is your sex?\n(Enter  m or f)");
        if (sex.equals("m")){
            JOptionPane.showMessageDialog(null, "Well done, you are male.\nKeep Going!");
        }
        int age = Integer.parseInt(sAge);
        String chars = JOptionPane.showInputDialog(null, "Name three charectaristics");
    }
}

If statement is ignored

4 Answers4