//
// Demonstrates how to check whether a floating‑point value (Double)
// is an integer (has no fractional part) in Scala.
// Uses a small tolerance to safely handle floating‑point precision issues.
// Scala's Double behaves like a standard IEEE‑754 double.
//
object DoubleIntegerCheck {
// ---------------------------------------------------------------------------
// Determines whether a Double represents an integer value.
// A tiny epsilon helps avoid floating‑point precision errors.
// ---------------------------------------------------------------------------
def isInteger(value: Double): Boolean = {
val epsilon: Double = 1e-12
// math.floor returns the largest integer <= value
val floored: Double = math.floor(value)
// If the absolute difference is extremely small, treat the number as integer
math.abs(value - floored) < epsilon
}
// ---------------------------------------------------------------------------
// Prints a descriptive message for the given Double.
// ---------------------------------------------------------------------------
def printCheck(value: Double): Unit = {
println(f"Checking value: $value%.15f")
if (isInteger(value))
println("Result: The value contains an integer.\n")
else
println("Result: The value contains a floating‑point number.\n")
}
// ---------------------------------------------------------------------------
// Entry point demonstrating several example values.
// ---------------------------------------------------------------------------
def main(args: Array[String]): Unit = {
// Example input values
val a: Double = 42.0 // integer-like
val b: Double = 42.00000000001 // floating-point due to tiny fraction
val c: Double = 89.0000000000001 // integer-like
val d: Double = -7.0 // negative integer-like
val e: Double = 3.14 // floating-point
// Run checks
printCheck(a)
printCheck(b)
printCheck(c)
printCheck(d)
printCheck(e)
}
}
/*
run:
Checking value: 42.000000000000000
Result: The value contains an integer.
Checking value: 42.000000000010000
Result: The value contains a floating?point number.
Checking value: 89.000000000000100
Result: The value contains an integer.
Checking value: -7.000000000000000
Result: The value contains an integer.
Checking value: 3.140000000000000
Result: The value contains a floating?point number.
*/
