CODEWITHSUNDEEP
javastringif-statement
Wilson
Wilson

Reputation: 8768

Why does my code always go to the else statement?

package GC;

import java.util.Scanner;

public class main {
public static void main(String args[]) {
    Scanner input = new Scanner(System.in);
    System.out.println("Calculate exam grade needed(e) or final grade received(f)?");
    String x = input.nextLine();
    if (x == "e"){
        double q1, q2, f, e;
        Scanner inputa = new Scanner(System.in);
        Scanner inputb = new Scanner(System.in);
        Scanner inputc = new Scanner(System.in);

        System.out.print("Quarter 1: ");
        q1 = inputa.nextInt();
        System.out.print("Quarter 2: ");
        q2 = inputb.nextInt();
        System.out.print("Final grade wanted: ");
        f = inputc.nextInt();

        e = 5*(f-0.4*(q1)-0.4*(q2));
        if(e == (int)e){
            System.out.println((int)e);
        }
        else{
            e = 0.01*((int)(e*100));
            System.out.println(e);
        }
    }


    else if (x == "f"){

    }
    else{
        System.out.println("ERROR");
    }



}
}

Even if I input e at the beginning, it always goes to the else statement. I may have done something wrong with getting a String from user input or with my if parameters. What am I missing?

Upvotes: 0

Views: 846

Answers (4)

amit
amit

Reputation: 178481

if (x == "e"){

You should compare String objects with equals() and not operator==. You should also be aware of equalsIgnoreCase(), which checks for equality of Strings, while ignoring which case each character is - it might be useful sometimes.

operator== checks for identity - if the two objects are actually the same object [the variables referencing the same object], while equals() is checking for equality - if their content is the same.

change

if (x == "e"){

to

if ("e".equals(x)) {

and do the same for else if (x == "f"){

Upvotes: 3

DavidB
DavidB

Reputation: 2234

You need to use the "equals" compare method. X is a string and there is no overloading operator for "==" on it to compare values.

Always take a look at the javadocs for an object if you're unsure.

http://docs.oracle.com/javase/6/docs/api/java/lang/String.html

if(x.equals("e")){

}

Upvotes: 1

Diego
Diego

Reputation: 36156

try (maybe you are getting a blank space:

String x = input.nextLine().toString().trim()

or

x.equals("e")

Upvotes: 0

ren
ren

Reputation: 3993

Because e is double and when you cast it to int you lose some bits.

Upvotes: 0

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