Avoid referential equality test for strings KT-E1005

Kotlin supports checking for equality in two ways; by comparing references, or by comparing the values stored in the references.

Kotlin's == operator is used to compare by value and is equivalent to calling the equals() method as defined in Java. To perform referential equality, one must use the === operator instead, which would correspond to the normal == operator from Java.

In general, it is better to use the == operator to compare objects, because even if two objects have different addresses, it is possible that their structure and/or state could be exactly the same.

Only use === when you need to know if two references are pointing to the same object or not.

It is better to use the == operator to compare objects such as Strings, as it provides stronger conditions for equality.

Bad Practice

val s1: String = "first string"
val s2: String = "second string"
if (s1 === s2) {
    // ...
}

Recommended

Use structural equality to compare strings.

val s1: String = "first string"
val s2: String = "second string"
if (s1 == s2) {
    // ...
}