Finding object in ArrayList via user input - Java

Question

I'm trying to display Car from fleet ArrayList using user input. Unfortunately I'm not sure how to go about it. I have found few examples online but cannot make them work. I have incorporated following method:

 void findRegNo(String reg){
     boolean exist=false;
        for(int i=0;i<this.fleet.size();i++){
            if(this.fleet.get(i).getRegNo() == reg){
                exist=true;
                break;
            }
        }

        if(exist) {
            System.out.println("!!!!!");
        } else {
            System.out.println("xxx");
        }    
}

At the moment the result is always: xxx so the code does not find any match. That function is placed in my container class, I was thinking that maybe it supposed to be in different location. These are variables of Car class:

public class Car {

    //defining variables
    String regNo;
    String model;
    double mileage;

Use String.equals to compare strings

Reimeus
– Reimeus

2015-04-26 21:15:28 +00:00
Commented Apr 26, 2015 at 21:15 — Reimeus
– Reimeus, Commented Apr 26, 2015 at 21:15

Mureinik · Accepted Answer · 2015-04-26 21:17:44Z

2

Strings are objects, not primitives. Hence, you should use equals to compare their value, not ==, which checks that both references are to the same object:

if (this.fleet.get(i).getRegNo().equals(reg)) {
    exist = true;
    break;
}

answered Apr 26, 2015 at 21:17

Mureinik

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1 Comment

Joe Doe Over a year ago

Thanks for that, was struggling for a bit with it.

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