CODEWITHSUNDEEP
kotlin
Gilli
Gilli

Reputation: 51

Checking if user entered data type int with if else statement Kotlin

EDIT: ANSWER TO THIS IS BELOW

Really new to kotlin, wanting to check if user entered an Integer, using if else statement. Need to add a do while loop to it later.

Expecting Error Message: Incorrect

When I hover over (input != pin) it displays Condition 'input != pin' is always true.

Here's my code

fun main() {
println("Create PIN: ")
val pin = readln().toInt()

println("Enter PIN: ")
val input = readln().toInt()

if (input == pin){
    println ("Correct")
}
else if (input != pin) {
    println("Incorrect")
}
}

Upvotes: 1

Views: 928

Answers (1)

Mohamed Rejeb
Mohamed Rejeb

Reputation: 2639

Because if input == pin is false so input != pin is always true, that's why you don't need the second else if you can just replace it with if:

fun main() {
    println("Create PIN: ")
    val pin = readln().toInt()

    println("Enter PIN: ")
    val input = readln().toInt()

    if (input == pin){
        println ("Correct")
    }
    else {
        println("Incorrect")
    }
}

But now if the user enters something that can't be converted to int ( some characters for example "hello"... ) .toInt() is going to throw a NumberFormatException and your code is not going to work so to fix that problem and handle the case when a user enters something other that Int, you can use .toIntOrNull() instead of .toInt().

.toIntOrNull(): Parses the string as an Int number and returns the result or null if the string is not a valid representation of a number.

So if pin or input is null, that mean that the user enters something that can't be converted to Int.

fun main() {
    println("Create PIN: ")
    val pin = readln().toIntOrNull()

    println("Enter PIN: ")
    val input = readln().toIntOrNull()

    if (input == null || pin == null) {
        println("PIN is not valid")
    }
    else if (input == pin){
        println ("Correct")
    }
    else {
        println("Incorrect")
    }
}

Upvotes: 3

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