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Thread: What's wrong with simple Scanner program?

  1. #1
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    Default What's wrong with simple Scanner program?

    import javax.swing.*;
    import java.util.*;
     
    public class Scanner1{
     
    	public static void main(String[] args){
     
    		String first, output;
    		Scanner scanner1 = new Scanner(System.in);
    		System.out.print("First: ");
    		first = scanner1.next();
     
     
    		JFrame mainWindow;
     
    		if (first == "a") {
    			output = "3.5" ;
    		}
    		else {
    			output = "No." ;
    		}
     
    		System.out.println(output);
     
    	}
    }


  2. #2
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    Default Re: What's wrong with simple Scanner program?

    The program compiles and runs however if I input a it does not output 3.5

  3. #3
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    Default Re: What's wrong with simple Scanner program?

    you cannot compare String object with "=="
    for String comparison
    use
    "a".equals(first)
    Thanks and Regards
    Dan Brown

    Common Java Mistakes

  4. #4
    mmm.. coffee JavaPF's Avatar
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    Default Re: What's wrong with simple Scanner program?

    As said by DanBrown.. This is a common Java mistake.

    Please read - Common Java Mistakes == operator or equals() method
    Problem category: Logic Problems
    Please use [highlight=Java] code [/highlight] tags when posting your code.
    Forum Tip: Add to peoples reputation by clicking the button on their useful posts.

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