Link Here (replay : yole)
Kotlin referential equality behavior on Int with values between -128 to 127 - Stack Overflow
Title : “Referential equality”
case #1
var numA: Int = 100
var numB: Int = 100
println(numA === numB) // Result : true
var numC: Int? = numA
println(numC === numA) // Result : true
case #2
var numA: Int = 1000
var numB: Int = 1000
println(numA === numB) // Result : true
var numC: Int? = numA
println(numC === numA) // Result : false
summary
1. println(numA === numB) : All Result is True
2. println(numC === numA) : Different Result
*Interest things -128 ~ 127 (is true)
another is false