I'm still doing point 8

bin/.gitignore

@@ -0,0 +1,2 @@
+/Spreadsheet.class
+/SpreadsheetTest.class

src/Spreadsheet.java

@@ -1,18 +1,83 @@
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 public class Spreadsheet {
 
+	private String excel[][] = new String[26][26];
+
+	private int AlphabetToNum(String str){
+		char[] ch  = str.toCharArray();
+		for(char c : ch)
+		{
+			int temp = (int)c;
+			int temp_integer = 64; //for upper case
+			if(temp<=90 & temp>=65)
+				return temp-temp_integer;
+		}
+		return 0;
+	 }
+
+	private boolean isCell(String split) {
+		// TODO Auto-generated method stub
+		String[] str = split.split("");
+
+		Pattern p = Pattern.compile("{upper}");
+		Pattern p2 = Pattern.compile("{digit}");
+		Matcher m = p.matcher(str[0]);
+		Matcher m2 = p2.matcher(str[1]);
+	    if (m.find() & m2.find())
+	    	return true;
+		return false;
+	}
+
 	public String get(String cell) {
-		// to be implemented
-		return null;
+
+		String[] str = cell.split("");
+
+		return excel[AlphabetToNum(str[0])][Integer.parseInt(str[1])];
+
 	}
 
 	public void set(String cell, String value) {
-		// to be implemented
+
+		String[] str = cell.split("");	
+		excel[AlphabetToNum(str[0])][Integer.parseInt(str[1])] = value;
 	}
 
 	public String evaluate(String cell) {
-		// to be implemented
-		return null;
+		int  resultNum=0;
+		int count=0;
+		String result="";
+
+		String data = get(cell);
+		String[] str = data.split("");
+
+		for(int i=0; i<str.length; i++){
+
+			switch(str[i]){
+				case "=":
+					if(isCell(data.split("=")[1]))
+
+					break;
+				case "-":
+					if(i-1<0)
+						resultNum = 0-Integer.parseInt(str[1]);
+						result = result + String.valueOf(resultNum);
+						break;
+				case "'":
+					String spl1 = data.split("'")[1];
+					if(count==1)
+						result = result + spl1;
+					count++;
+					break;
+			}
+		}
+
+		if(result!="")
+			return result;
+
+		return "#Error";
+
 	}
 
 }

tests/SpreadsheetTest.java

@@ -7,9 +7,66 @@
 public class SpreadsheetTest {
 
 	@Test
-	public void test() {
+	public void test() {		
 		fail("Not yet implemented");
 
 	}
+
+	@Test
+	public void testSetup(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("A1", "1");
+		assertEquals("1",sp.get("A1"));
+	}
+
+	@Test
+	public void testNumber_handling(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("A1", "-1");
+		assertEquals("-1",sp.evaluate("A1"));
+
+	}
+
+	@Test
+	public void testWrongly_formatted_integers(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("B1", "A%");
+		assertEquals("#Error",sp.evaluate("B1"));
+	}
+
+	@Test
+	public void testString_handling(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("B3", "'a string'");
+		assertEquals("a string",sp.evaluate("B3"));
+	}
+
+	@Test
+	public void testUnquoted_strings(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("B3", "'a string");
+		assertEquals("#Error",sp.evaluate("B3"));
+	}
+
+	@Test
+	public void testSimple_formulas(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("B3", "='a string'");
+		assertEquals("a string",sp.evaluate("B3"));
+	}
+
+	@Test
+	public void testCell_references(){
+		Spreadsheet sp = new Spreadsheet();
+
+		sp.set("A1", "=A5");
+		assertEquals("#Circular",sp.evaluate("A1"));
+	}
 
 }