I'm from the java android background. So can someone explain why a variable with type String? cannot be equal to a variable of type String.
var a: String? = "Kotlin"
var b: String = "Kotlin"
b = a // Gives error
What's the difference in both the types ? Can anyone explain in java ?
In kotlin the "?" keyword indicates that a data type can take a null value. Variable "a" can take a null value, but variable "b" can not take a null value. You would need to make sure that "a" is not null before you could assign that value to "b".
If you want to assign the value of a to b you can do like this
var a: String? = "Kotlin"
var b: String = "Kotlin"
b= a?:"" -----> if a is null at some point of time in your code then b would be assigned an empty value
or
b= a.toString() -----> if a is null at ssome point of time in your code then b would be assigned "null" string value
The following prints "it's the same". Are you using the correct comparison operator?
var a: String? = "Kotlin"
var b: String = "Kotlin"
if (a == b){
println("it's the same");
}
else{
println("it's not the same!")
}
