Sum 在 Kotlin 中给出一个负数

Question

So here is my Kotlin Code:

val intBoth = 1_391_000_000 + 1_432_342_859

println("China plus India: " + intBoth)

And the result is negative:

China plus India: -1471624437

What went wrong here?

Answer 1

If you you don't select a your variable type (like Long,Float,Bytes,Shorts ), the kotlin asumes it is an Integer .

The variable types have boundary conditions for representing number values.

The boundary of Integers are between -2,147,483,648 and 2,147,483,647 (It's about byte of size). The variables of your calculation of summiation are Integer so the complier expect the total value is Integer, but the result is out of the range of Integer variable type. Yo can overcome the problem by convert to Long your types of elements. Write .toLong end of the variables for converting

fun main() {
  val intBoth = 1391000000.toLong() + 1432342859.toLong()

println("China plus India: " + intBoth)
          
}