Arrays

StringArrayUtils.java

@@ -1,4 +1,4 @@
- 
+ import java.util.Arrays;
 
 /**
  * Created by leon on 1/29/18.
@@ -9,7 +9,7 @@ public class StringArrayUtils {
      * @return first element of specified array
      */ // TODO
     public static String getFirstElement(String[] array) {
-        return null;
+        return array[0];
     }
 
     /**
@@ -17,7 +17,7 @@ public class StringArrayUtils {
      * @return second element in specified array
      */
     public static String getSecondElement(String[] array) {
-        return null;
+        return array[1];
     }
 
     /**
@@ -25,7 +25,7 @@ public class StringArrayUtils {
      * @return last element in specified array
      */ // TODO
     public static String getLastElement(String[] array) {
-        return null;
+        return array[array.length-1];
     }
 
     /**
@@ -33,7 +33,7 @@ public class StringArrayUtils {
      * @return second to last element in specified array
      */ // TODO
     public static String getSecondToLastElement(String[] array) {
-        return null;
+        return array[array.length-2];
     }
 
     /**
@@ -42,7 +42,19 @@ public class StringArrayUtils {
      * @return true if the array contains the specified `value`
      */ // TODO
     public static boolean contains(String[] array, String value) {
-        return false;
+        boolean a = true;
+        
+        for(int i = 0; i <= array.length; i++){
+            if(array[i].equals(value)){
+                a = true;
+                break;
+            }
+            else{
+                a = false;
+            }
+        }
+        
+        return a;
     }
 
     /**
@@ -50,7 +62,14 @@ public class StringArrayUtils {
      * @return an array with identical contents in reverse order
      */ // TODO
     public static String[] reverse(String[] array) {
-        return null;
+        String[] result = new String[array.length];
+        
+        for (int i = 0; i< array.length; i++){
+            result[i] = 
+            array[array.length-i-1];
+        }
+        
+        return result;
     }
 
     /**
@@ -58,7 +77,23 @@ public class StringArrayUtils {
      * @return true if the order of the array is the same backwards and forwards
      */ // TODO
     public static boolean isPalindromic(String[] array) {
-        return false;
+        int length = array.length;
+        
+        for (int index = 0; index < array.length; index++) {
+        String start = array[index];
+        
+        String end = array[--length];
+        
+        if (length < index) {
+            return true;
+        }
+        
+        if (start != end) {
+            return false;
+        }
+       }
+        
+        return true;
     }
 
     /**
@@ -66,7 +101,19 @@ public class StringArrayUtils {
      * @return true if each letter in the alphabet has been used in the array
      */ // TODO
     public static boolean isPangramic(String[] array) {
-        return false;
+        String arrayToString = array.toString();
+        String str = arrayToString.toLowerCase();
+        
+        boolean answer = true;
+        
+        for(char c = 'a';c <= 'z'; ++c) {
+            if(!str.contains(String.valueOf(c))) {
+                answer = false;
+                break;
+            }
+        }
+
+        return answer;
     }
 
     /**
@@ -75,7 +122,15 @@ public class StringArrayUtils {
      * @return number of occurrences the specified `value` has occurred
      */ // TODO
     public static int getNumberOfOccurrences(String[] array, String value) {
-        return 0;
+        int counter = 0;
+        
+        for(int i = 0; i <= array.length-1; i++){
+            if(array[i].equals(value)){
+                counter = counter + 1;
+            }
+        }
+        
+        return counter;
     }
 
     /**
@@ -84,7 +139,24 @@ public class StringArrayUtils {
      * @return array with identical contents excluding values of `value`
      */ // TODO
     public static String[] removeValue(String[] array, String valueToRemove) {
-        return null;
+        int count = 0;
+        
+        for(int i = 0; i < array.length; i++){
+            if(array[i].equals(valueToRemove)){
+                count = count + 1;
+            }
+        }
+        
+        String[] newArray = new String[array.length - count];
+        
+        int j = 0;
+        for(int i = 0; i < array.length; i++){
+            if(!array[i].equals(valueToRemove)){
+                newArray[j++] = array[i];
+            }
+        }
+        
+        return newArray;
     }
 
     /**
@@ -92,16 +164,58 @@ public class StringArrayUtils {
      * @return array of Strings with consecutive duplicates removes
      */ // TODO
     public static String[] removeConsecutiveDuplicates(String[] array) {
-        return null;
+        int dupCounter = 0;
+        
+        for(int i = 0; i < array.length-1; i++){
+            if(array[i].equals(array[i+1])){
+                dupCounter = dupCounter + 1;
+            }
+        }
+        
+        String[] newArray = new String[array.length - dupCounter];
+        
+        //String [] newArray = new String[array.length];
+        
+        int j = 0;
+        for(int i = 0; i < array.length-1; i++){
+            if(!array[i].equals(array[i + 1])){
+                newArray[j++] = (array[i]);
+            }
+        }
+        
+        newArray[newArray.length-1] = array[array.length-1];
+        
+        return newArray;
     }
 
     /**
      * @param array array of chars
-     * @return array of Strings with each consecutive duplicate occurrence concatenated as a single string in an array of Strings
+     * @return array of Strings with each consecutive duplicate occurrence concatenated 
+     * @as a single string in an array of Strings
      */ // TODO
     public static String[] packConsecutiveDuplicates(String[] array) {
-        return null;
-    }
-
+        //StringBuilder sb = new StringBuilder();
+        
+        int dupCounter = 0;
+        
+        for(int i = 0; i < array.length-1; i++){
+            if(array[i].equals(array[i+1])){
+                dupCounter = dupCounter + 1;
+            }
+        }
+        
+        String[] newArray = new String[array.length - dupCounter];
+        
+        int j = 0;
+        for(int i = 0; i < array.length-1; i++){
+            if(array[i].equals(array[i+1])){
+                StringBuilder sb = new StringBuilder(array[i]);
+                sb.append(array[i+1]);
+                
+                newArray[j++] = (array[i]);
+            }
+        }
 
+        return newArray;
+    }
 }

StringArrayUtilsTest.java

@@ -341,7 +341,6 @@ public class StringArrayUtilsTest {
     }
 
 
-
     @Test
     public void testRemoveConsecutiveDuplicates2() {
         String[] array = {"aba", "aba", "baa", "bab", "bba", "zzz", "bba", "bba", "bba", "bbb", "bbb"};

package.bluej

@@ -0,0 +1,42 @@
+#BlueJ package file
+dependency1.from=StringArrayUtilsTest
+dependency1.to=StringArrayUtils
+dependency1.type=UsesDependency
+editor.fx.0.height=0
+editor.fx.0.width=0
+editor.fx.0.x=0
+editor.fx.0.y=0
+objectbench.height=101
+objectbench.width=461
+package.divider.horizontal=0.6
+package.divider.vertical=0.8007380073800738
+package.editor.height=427
+package.editor.width=674
+package.editor.x=114
+package.editor.y=-921
+package.frame.height=600
+package.frame.width=800
+package.numDependencies=1
+package.numTargets=2
+package.showExtends=true
+package.showUses=true
+project.charset=UTF-8
+readme.height=58
+readme.name=@README
+readme.width=47
+readme.x=10
+readme.y=10
+target1.height=50
+target1.name=StringArrayUtilsTest
+target1.showInterface=false
+target1.type=UnitTestTargetJunit4
+target1.width=150
+target1.x=130
+target1.y=10
+target2.height=50
+target2.name=StringArrayUtils
+target2.showInterface=false
+target2.type=ClassTarget
+target2.width=120
+target2.x=70
+target2.y=70