Is `==` and `equals` same in Kotlin? If so, can so...

# getting-started

[blue]

Is == and equals same in Kotlin? If so, can someone help me why my program is returning false for below inputs

John 19 0
John 19 22

import java.util.*

data class Client(val name: String, val age: Int, val balance: Int) {
    fun equals(other: Client?): Boolean {
        return this.age == other?.age && this.name == other.name
    }
}

fun main(args: Array<String>) {
    val input = Scanner(System.`in`)

    val n = input.next()
    val a = input.nextInt()
    val b = input.nextInt()

    val nn = input.next()
    val aa = input.nextInt()
    val bb = input.nextInt()

    println(Client(n, a, b) == (Client(nn, aa, bb)))
}

[blue]

also found this quote on Stackoverflow

In Kotlin == is compiled to equals, whereas === is the equivalent of Java’s ==.

[zsperske]

have you tried changing your .equals to

[zsperske]

override fun equals(other: Any?): Boolean

[zsperske]

i think you've just defined another method that isn't actually used

[blue]

.equals is working, but I thought == works same as .equals

[zsperske]

yes but in order for == to actually call your .equals method

[zsperske]

it needs to use the signature I provided above

[blue]

Ohk. Got it now

[blue]

Thanks

[zsperske]

np! the override keyword was required as well as using the correct method signature since .equals and == allow any value to be passed, not just another object of the same type

[blue]

and I need to learn Casting 🙂

[zsperske]

as? can be very useful but of course, always be careful with when you use casts

[nanodeath]

IntelliJ can also Generate equals and hashcode for you, and it's usually a good idea to override both, per Effective Java's recommendation

[Michael de Kaste]

I would btw not put relevant parameters in the primary constructor in this case. Data classes autogenerates an equals function for you, so you dont have to. In your case, I would solve it as followed:

data class Client private constructor(val name: String, val age : Int){
    var balance: Int = 0
        private set
    
    constructor(name: String, age: Int, balance: Int) : this(name, age){
        this.balance = balance
    }
}