baeldung-articles : BAEL-7180 (#15616)

Check if a float value is equivalent to an integer value in Java.

core-java-modules/core-java-numbers-7/src/test/java/com/baeldung/checkiffloatequivalenttointeger/CheckIfFloatEquivalentToIntegerUnitTest.java

@@ -0,0 +1,64 @@
+package com.baeldung.checkiffloatequivalenttointeger;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.util.Scanner;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class CheckIfFloatEquivalentToIntegerUnitTest {
+    float floatValue = 10.0f;
+
+    @Test
+    public void givenFloatAndIntValues_whenCastingToInt_thenCheckIfFloatValueIsEquivalentToIntegerValue() {
+        int intValue = (int) floatValue;
+
+        assertEquals(floatValue, intValue);
+    }
+
+    @Test
+    public void givenFloatAndIntValues_whenUsingTolerance_thenCheckIfFloatValueIsEquivalentToIntegerValue() {
+        int intValue = 10;
+        float tolerance = 0.0001f;
+
+        assertTrue(Math.abs(floatValue - intValue) <= tolerance);
+    }
+
+    @Test
+    public void givenFloatAndIntValues_whenUsingFloatCompare_thenCheckIfFloatValueIsEquivalentToIntegerValue() {
+        int intValue = 10;
+
+        assertEquals(Float.compare(floatValue, intValue), 0);
+    }
+
+    @Test
+    public void givenFloatAndIntValues_wheUsingRound_thenCheckIfFloatValueIsEquivalentToIntegerValue() {
+        int intValue = 10;
+
+        assertEquals(intValue, Math.round(floatValue));
+    }
+
+    @Test
+    public void givenFloatAndIntValues_whenUsingScanner_thenCheckIfFloatValueIsEquivalentToIntegerValue() {
+        String input = "10.0";
+        Scanner sc = new Scanner(new ByteArrayInputStream(input.getBytes()));
+
+        float actualFloatValue;
+        if (sc.hasNextInt()) {
+            int intValue = sc.nextInt();
+            actualFloatValue = intValue;
+        } else if (sc.hasNextFloat()) {
+            actualFloatValue = sc.nextFloat();
+
+        } else {
+            actualFloatValue = Float.NaN;
+        }
+
+        sc.close();
+
+        assertEquals(floatValue, actualFloatValue);
+    }
+
+}