In kotlin class, I have method parameter as object (See kotlin doc here ) for class type T. As object I am passing different classes when I am calling method.
In Java we can able to compare class using instanceof
of object which class it is.
So I want to check and compare at runtime which Class it is?
How can I check instanceof class in kotlin?
Use is
.
if (myInstance is String) { ... }
or the reverse !is
if (myInstance !is String) { ... }
We can check whether an object conforms to a given type at runtime by using the is
operator or its negated form !is
.
Example:
if (obj is String) {
print(obj.length)
}
if (obj !is String) {
print("Not a String")
}
Another Example in case of Custom Object:
Let, I have an obj
of type CustomObject
.
if (obj is CustomObject) {
print("obj is of type CustomObject")
}
if (obj !is CustomObject) {
print("obj is not of type CustomObject")
}
Combining when
and is
:
when (x) {
is Int -> print(x + 1)
is String -> print(x.length + 1)
is IntArray -> print(x.sum())
}
copied from official documentation
You can use is
:
class B
val a: A = A()
if (a is A) { /* do something */ }
when (a) {
someValue -> { /* do something */ }
is B -> { /* do something */ }
else -> { /* do something */ }
}
Try using keyword called is
Official page reference
if (obj is String) {
// obj is a String
}
if (obj !is String) {
// // obj is not a String
}