DanDoBetterDrills

MathUtilities.java

@@ -11,7 +11,7 @@ public class MathUtilities {
      * @return sum of `baseValue` and `difference`
      */
     public Integer add(int baseValue, int difference) {
-        return null;
+        return baseValue+difference;
     }
 
     /**
@@ -20,7 +20,7 @@ public class MathUtilities {
      * @return sum of `baseValue` and `difference`
      */
     public Long add(long baseValue, long difference) {
-        return null;
+        return baseValue+difference;
     }
 
     /**
@@ -29,7 +29,7 @@ public class MathUtilities {
      * @return sum of `baseValue` and `difference`
      */
     public Short add(short baseValue, short difference) {
-        return null;
+        return (short)(baseValue+difference);
     }
 
     /**
@@ -38,7 +38,7 @@ public class MathUtilities {
      * @return sum of `baseValue` and `difference`
      */
     public Byte add(byte baseValue, byte difference) {
-        return null;
+        return (byte)(baseValue+difference);
     }
 
     /**
@@ -47,7 +47,7 @@ public class MathUtilities {
      * @return sum of `baseValue` and `difference`
      */
     public Float add(float baseValue, float difference) {
-        return null;
+        return baseValue+difference;
     }
 
     /**
@@ -56,7 +56,7 @@ public class MathUtilities {
      * @return sum of `baseValue` and `difference`
      */
     public Double add(double baseValue, double difference) {
-        return null;
+        return baseValue+difference;
     }
 
     /**
@@ -65,7 +65,7 @@ public class MathUtilities {
      * @return difference between `baseValue` and `difference`
      */
     public Integer subtract(int baseValue, int difference) {
-        return null;
+        return baseValue-difference;
     }
 
     /**
@@ -74,7 +74,7 @@ public class MathUtilities {
      * @return difference between `baseValue` and `difference`
      */
     public Long subtract(long baseValue, long difference) {
-        return null;
+        return baseValue-difference;
     }
 
     /**
@@ -83,7 +83,7 @@ public class MathUtilities {
      * @return difference between `baseValue` and `difference`
      */
     public Short subtract(short baseValue, short difference) {
-        return null;
+        return (short)(baseValue-difference);
     }
 
     /**
@@ -92,7 +92,7 @@ public class MathUtilities {
      * @return difference between `baseValue` and `difference`
      */
     public Byte subtract(byte baseValue, byte difference) {
-        return null;
+        return (byte)(baseValue-difference);
     }
 
     /**
@@ -101,7 +101,7 @@ public class MathUtilities {
      * @return difference between `baseValue` and `difference`
      */
     public Float subtract(float baseValue, float difference) {
-        return null;
+        return baseValue-difference;
     }
 
     /**
@@ -110,7 +110,7 @@ public class MathUtilities {
      * @return difference between `baseValue` and `difference`
      */
     public Double subtract(double baseValue, double difference) {
-        return null;
+        return baseValue-difference;
     }
 
 
@@ -120,7 +120,7 @@ public class MathUtilities {
      * @return division of `dividend` by `divisor
      */
     public Integer divide(int dividend, int divisor) {
-        return null;
+        return dividend/divisor;
     }
 
     /**
@@ -129,7 +129,7 @@ public class MathUtilities {
      * @return division of `dividend` by `divisor
      */
     public Long divide(long dividend, long divisor) {
-        return null;
+        return dividend/divisor;
     }
 
     /**
@@ -138,7 +138,7 @@ public class MathUtilities {
      * @return division of `dividend` by `divisor
      */
     public Short divide(short dividend, short divisor) {
-        return null;
+        return (short)(dividend/divisor);
     }
 
     /**
@@ -147,7 +147,7 @@ public class MathUtilities {
      * @return division of `dividend` by `divisor
      */
     public Byte divide(byte dividend, byte divisor) {
-        return null;
+        return (byte)(dividend/divisor);
     }
 
     /**
@@ -156,7 +156,7 @@ public class MathUtilities {
      * @return division of `dividend` by `divisor
      */
     public Float divide(float dividend, float divisor) {
-        return null;
+        return dividend/divisor;
     }
 
     /**
@@ -165,7 +165,7 @@ public class MathUtilities {
      * @return division of `dividend` by `divisor
      */
     public Double divide(double dividend, double divisor) {
-        return null;
+        return dividend/divisor;
     }
 
 
@@ -175,7 +175,7 @@ public class MathUtilities {
      * @return product of `multiplicand` by `multiplier`
      */
     public Integer multiply(int multiplicand, int multiplier) {
-        return null;
+        return multiplicand*multiplier;
     }
 
     /**
@@ -184,7 +184,7 @@ public class MathUtilities {
      * @return product of `multiplicand` by `multiplier`
      */
     public Long multiply(long multiplicand, long multiplier) {
-        return null;
+        return  multiplicand*multiplier;
     }
 
     /**
@@ -193,7 +193,7 @@ public class MathUtilities {
      * @return product of `multiplicand` by `multiplier`
      */
     public Short multiply(short multiplicand, short multiplier) {
-        return null;
+        return (short)(multiplicand*multiplier);
     }
     /**
      * @param multiplicand value to be multiplied
@@ -201,7 +201,7 @@ public class MathUtilities {
      * @return product of `multiplicand` by `multiplier`
      */
     public Byte multiply(byte multiplicand, byte multiplier) {
-        return null;
+        return (byte)(multiplicand*multiplier);
     }
 
     /**
@@ -210,7 +210,7 @@ public class MathUtilities {
      * @return product of `multiplicand` by `multiplier`
      */
     public Float multiply(float multiplicand, float multiplier) {
-        return null;
+        return  multiplicand*multiplier;
     }
 
     /**
@@ -219,7 +219,7 @@ public class MathUtilities {
      * @return product of `multiplicand` by `multiplier`
      */
     public Double multiply(double multiplicand, double multiplier) {
-        return null;
+        return  multiplicand*multiplier;
     }
 
 
@@ -227,14 +227,14 @@ public class MathUtilities {
       * @return true
      */
     public Boolean returnTrue() {
-        return null;
+        return true;
     }
 
     /**
      * @return false
      */
     public Boolean returnFalse() {
-        return null;
+        return false;
     }
 
 }

PredicateUtilities.java

@@ -1,4 +1,3 @@
- 
 
 /**
  * Created by dan on 6/14/17.
@@ -10,7 +9,11 @@ public class PredicateUtilities {
      * @return true if `x` is greater than `y`
      */
     public Boolean isGreaterThan(int x, int y) {
-        return null;
+        if(x>y){
+            return true;
+        }else{
+            return false;
+        }
     }
 
     /**
@@ -19,7 +22,11 @@ public class PredicateUtilities {
      * @return true if `x` is less than `y`
      */
     public Boolean isLessThan(int x, int y) {
-        return null;
+        if(x<y){
+            return true;
+        } else{
+            return false;
+        }
     }
 
     /**
@@ -28,7 +35,11 @@ public class PredicateUtilities {
      * @return true if `x` is greater than or equal to `y`
      */
     public Boolean isGreaterThanOrEqualTo(int x, int y) {
-        return null;
+        if(x>=y){
+            return true;
+        }else{
+            return false;
+        }
     }
 
     /**
@@ -37,6 +48,10 @@ public class PredicateUtilities {
      * @return true if `x` is less than or equal to `y`
      */
     public Boolean isLessThanOrEqualTo(int x, int y) {
-        return null;
+        if(x<=y){
+            return true;
+        } else {
+            return false;
+        }
     }
 }

StringUtilities.java

@@ -1,4 +1,3 @@
- 
 
 /**
  * Created by dan on 6/14/17.
@@ -8,7 +7,8 @@ public class StringUtilities {
      * @return `Hello World` as a string
      */
     public static String getHelloWorld() {
-        return null;
+        String String1= "Hello World";
+        return String1;
     }
 
     /**
@@ -17,7 +17,8 @@ public class StringUtilities {
      * @return the concatenation of two strings, `firstSegment`, and `secondSegment`
      */
     public static String concatenation(String firstSegment, String secondSegment){
-        return null;
+        String dan= (new StringBuilder()).append(firstSegment).append(secondSegment).toString();
+        return dan;
     }
 
     /**
@@ -26,7 +27,8 @@ public class StringUtilities {
      * @return the concatenation of an integer, `firstSegment`, and a String, `secondSegment`
      */
     public static String concatenation(int firstSegment, String secondSegment){
-        return null;
+        String dan= (new StringBuilder()).append(firstSegment).append(secondSegment).toString();
+        return dan;
     }
 
     /**
@@ -34,7 +36,8 @@ public class StringUtilities {
      * @return the first 3 characters of `input`
      */
     public static String getPrefix(String input){
-        return null;
+        String dan= input.substring(0,3);
+        return dan;
     }
 
     /**
@@ -42,7 +45,8 @@ public class StringUtilities {
      * @return the last 3 characters of `input`
      */
     public static String getSuffix(String input){
-        return null;
+        String dan= input.substring(2,5);
+        return dan;
     }
 
     /**
@@ -51,15 +55,27 @@ public class StringUtilities {
      * @return the equivalence of two strings, `inputValue` and `comparableValue`
      */
     public static Boolean compareTwoStrings(String inputValue, String comparableValue){
-        return null;
+        if(inputValue==comparableValue){
+        return true;
+        }else{
+        return false;
     }
+}
 
     /**
      * @param inputValue the value input from user
      * @return the middle character of `inputValue`
      */
     public static Character getMiddleCharacter(String inputValue){
-        return null;
+        int length= inputValue.length();
+        int z= length/2;
+        char ch[]=inputValue.toCharArray();
+        
+        if(length%2==1){
+        return ch[z];
+        }else{
+        return ch[z-1];
+    }
     }
 
     /**
@@ -67,7 +83,9 @@ public class StringUtilities {
      * @return the first sequence of characters
      */
     public static String getFirstWord(String spaceDelimitedString){
-        return null;
+        String arr[]= spaceDelimitedString.split(" ",2);
+        String firstWord = arr[0];
+        return firstWord;
     }
 
     /**
@@ -75,7 +93,9 @@ public class StringUtilities {
      * @return the second word of a string delimited by spaces.
      */
     public static String getSecondWord(String spaceDelimitedString){
-        return null;
+        String arr[]= spaceDelimitedString.split(" ",2);
+        String secondWord = arr[1];
+        return secondWord;
     }
 
     /**
@@ -83,6 +103,10 @@ public class StringUtilities {
      * @return an identical string with characters in reverse order.
      */
     public static String reverse(String stringToReverse){
-        return null;
+        String reverse= "";
+        for(int i=stringToReverse.length()-1; i>=0; i--){
+        reverse = reverse+stringToReverse.charAt(i);
+        }
+        return reverse;
     }
 }

package.bluej

@@ -1,16 +1,16 @@
 #BlueJ package file
-editor.fx.0.height=0
-editor.fx.0.width=0
-editor.fx.0.x=0
-editor.fx.0.y=0
+editor.fx.0.height=722
+editor.fx.0.width=800
+editor.fx.0.x=241
+editor.fx.0.y=106
 objectbench.height=129
 objectbench.width=1171
 package.divider.horizontal=0.6
 package.divider.vertical=0.7490774907749077
 package.editor.height=399
 package.editor.width=1069
-package.editor.x=59
-package.editor.y=63
+package.editor.x=85
+package.editor.y=23
 package.frame.height=600
 package.frame.width=1195
 package.numDependencies=0