When writing about the hash code, use 'hash code', the compound 'hashcode' is not a work in English. The text 'hashCode()' is left as in of course.

src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java

@@ -101,7 +101,7 @@ public class EqualsBuilder implements Builder<Boolean> {
      *
      * So we generate a one-to-one mapping from the original object to a new object.
      *
-     * Now HashSet uses equals() to determine if two elements with the same hashcode really
+     * Now HashSet uses equals() to determine if two elements with the same hash code really
      * are equal, so we also need to ensure that the replacement objects are only equal
      * if the original objects are identical.
      *

src/main/java/org/apache/commons/lang3/builder/HashCodeBuilder.java

@@ -42,7 +42,7 @@ import org.apache.commons.lang3.Validate;
  * The following is the approach taken. When appending a data field, the current total is multiplied by the
  * multiplier then a relevant value
  * for that data type is added. For example, if the current hashCode is 17, and the multiplier is 37, then
- * appending the integer 45 will create a hashcode of 674, namely 17 * 37 + 45.
+ * appending the integer 45 will create a hash code of 674, namely 17 * 37 + 45.
  * </p>
  *
  * <p>
@@ -126,7 +126,7 @@ public class HashCodeBuilder implements Builder<Integer> {
      *
      * So we generate a one-to-one mapping from the original object to a new object.
      *
-     * Now HashSet uses equals() to determine if two elements with the same hashcode really
+     * Now HashSet uses equals() to determine if two elements with the same hash code really
      * are equal, so we also need to ensure that the replacement objects are only equal
      * if the original objects are identical.
      *

src/main/java/org/apache/commons/lang3/builder/IDKey.java

@@ -35,7 +35,7 @@ final class IDKey {
          * @param _value The value
          */ 
         public IDKey(final Object _value) {
-            // This is the Object hashcode 
+            // This is the Object hash code 
             id = System.identityHashCode(_value);  
             // There have been some cases (LANG-459) that return the 
             // same identity hash code for different objects.  So 
@@ -44,7 +44,7 @@ final class IDKey {
         }
 
         /**
-         * returns hashcode - i.e. the system identity hashcode.
+         * returns hash code - i.e. the system identity hashcode.
          * @return the hashcode
          */ 
         @Override

src/main/java/org/apache/commons/lang3/builder/ToStringStyle.java

@@ -2314,7 +2314,7 @@ public abstract class ToStringStyle implements Serializable {
 
     /**
      * <p><code>ToStringStyle</code> that does not print out the classname
-     * and identity hashcode but prints content start and field names.</p>
+     * and identity hash code but prints content start and field names.</p>
      *
      * <p>This is an inner class rather than using
      * <code>StandardToStringStyle</code> to ensure its immutability.</p>

src/main/java/org/apache/commons/lang3/math/Fraction.java

@@ -848,7 +848,7 @@ public final class Fraction extends Number implements Comparable<Fraction> {
     @Override
     public int hashCode() {
         if (hashCode == 0) {
-            // hashcode update should be atomic.
+            // hash code update should be atomic.
             hashCode = 37 * (37 * 17 + getNumerator()) + getDenominator();
         }
         return hashCode;

src/main/java/org/apache/commons/lang3/time/FastDateFormat.java

@@ -636,9 +636,9 @@ public class FastDateFormat extends Format implements DateParser, DatePrinter {
     }
 
     /**
-     * <p>Returns a hashcode compatible with equals.</p>
+     * <p>Returns a hash code compatible with equals.</p>
      *
-     * @return a hashcode compatible with equals
+     * @return a hash code compatible with equals
      */
     @Override
     public int hashCode() {

src/main/java/org/apache/commons/lang3/time/FastDateParser.java

@@ -308,9 +308,9 @@ public class FastDateParser implements DateParser, Serializable {
     }
 
     /**
-     * <p>Return a hashcode compatible with equals.</p>
+     * <p>Return a hash code compatible with equals.</p>
      *
-     * @return a hashcode compatible with equals
+     * @return a hash code compatible with equals
      */
     @Override
     public int hashCode() {

src/main/java/org/apache/commons/lang3/time/FastDatePrinter.java

@@ -637,9 +637,9 @@ public class FastDatePrinter implements DatePrinter, Serializable {
     }
 
     /**
-     * <p>Returns a hashcode compatible with equals.</p>
+     * <p>Returns a hash code compatible with equals.</p>
      *
-     * @return a hashcode compatible with equals
+     * @return a hash code compatible with equals
      */
     @Override
     public int hashCode() {