In this post we will discuss about one of the basic java interview question and question is that What will this statement return 3*0.1 == 0.3? true or false?
This is one of the really most tricky interview question in java. Only few developers answer this question and explain the concept correctly. The very short and crispy answer is false because some floating-point numbers cannot be represented exactly.
Let’s understand above concept using an example
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package com.kkjavatutorials.client; /** * @author KK JavaTutorials *What will this statement return 3*0.1 == 0.3? true or false? */ public class Test { public static void main(String[] args) { double d1 = 3 * 0.1; double d2 = 0.3; System.out.println("d1 = "+d1); System.out.println("d2 = "+d2); //Some floating-point numbers cannot be represented exactly so i will print false. System.out.println(d1==d2); double d3 = 100.0; double d4 = 100.0; System.out.println("d3 = "+d3); System.out.println("d4 = "+d4); //This will return true System.out.println(d3==d4); } } |
Sample Output
d1 = 0.30000000000000004
d2 = 0.3
false
d3 = 100.0
d4 = 100.0
true
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