1-8,10

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task1.java

@@ -2,6 +2,8 @@
 
 public class Task1 {
     public static String makeTags(String tag, String text) {
-        return "";
+
+
+        return "<"+tag+">"+text+"</"+tag+">";
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task10.java

@@ -2,6 +2,11 @@
 
 public class Task10 {
     public static String trim(String text) {
-        return "";
+
+        if(text==null){return null;}
+        String resultString = text.trim();
+
+
+        return resultString;
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task2.java

@@ -3,6 +3,8 @@
 
 public class Task2 {
     public static String firstTwo(String s) {
-        return "";
+       if(s.length()<=2){return s;}
+        else return s.substring(0,2);
+
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task3.java

@@ -3,6 +3,11 @@
 
 public class Task3 {
     public static String comboString(String s1, String s2) {
-        return "";
-    }
+if(s1==null){s1="null";}
+        if(s2==null){s2="null";}
+        if(s1.length()>=s2.length()){
+        return s2+s1+s2;}
+        else return s1+s2+s1;
+
+            }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task4.java

@@ -2,6 +2,11 @@
 
 public class Task4 {
     public static String charAt(String s, int i) {
-        return "";
+        int realCharAt=0;
+        if (i>=0&& s.length()>=i){realCharAt=i;}
+        else if (i>s.length()){realCharAt=i%(s.length());}
+        else if (i<0){realCharAt=s.length()+(i%(s.length()));}
+        if(realCharAt==s.length()){realCharAt=0;}
+        return  s.substring(realCharAt,realCharAt+1);
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task5.java

@@ -2,6 +2,10 @@
 
 public class Task5 {
     public static boolean commondEnd(int[] a, int[] b) {
+        if (a[0] == b[0]||a[a.length-1]==b[0]||a[0]==b[b.length-1]||a[a.length-1]==b[b.length-1]) {
+
+return true;        }
+
         return false;
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task6.java

@@ -3,6 +3,13 @@
 
 public class Task6 {
     public static int[] reverse(int[] arr) {
-        return null;
+        if (arr==null){return null;}
+        for(int i=0;i<(arr.length)/2;i++){
+
+         int temp=arr[i];
+            arr[i]=arr[arr.length-1-i];
+            arr[arr.length-1-i]=temp;
+                    }
+        return arr;
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task7.java

@@ -1,7 +1,19 @@
 package school.lemon.changerequest.java.introduction.hw2;
 
+
+
 public class Task7 {
     public static int countEvens(int[] arr) {
-        return 0;
+        int count =0;
+        if(arr==null){return 0;}
+        for(int i=0; i<arr.length; i++){
+            if (arr[i]%2==0||arr[i]==0){count=count+1;}
+
+
+        }
+
+
+
+        return count;
     }
 }

src/main/java/school/lemon/changerequest/java/introduction/hw2/Task9.java

@@ -1,7 +1,18 @@
 package school.lemon.changerequest.java.introduction.hw2;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 public class Task9 {
     public static String[] extractData(String URL) {
-        return new String[]{"", "", ""};
+        String []array=new String[3];
+
+        String scheme =("[a-z]*(?=://)");
+        Pattern p1 = Pattern.compile(scheme);
+        Matcher m1 = p1.matcher(URL);
+        if(m1.find()){array[0]=m1.group();}
+
+        return array;
     }
 }
+