diff --git a/src/CustomerProperties.h b/src/CustomerProperties.h
index 2bbab62..e2ba317 100644
--- a/src/CustomerProperties.h
+++ b/src/CustomerProperties.h
@@ -1,4 +1,5 @@
 typedef struct Customer{
-	char *ID, *forename, *surname, *password;
+	int ID;
+	char *forename,*surname,*password;
 	float balance;
 }customer_t;
diff --git a/src/StringManipulation.c b/src/StringManipulation.c
new file mode 100644
index 0000000..7ac306e
--- /dev/null
+++ b/src/StringManipulation.c
@@ -0,0 +1,68 @@
+#include "StringManipulation.h"
+/*Code written by Julius Philipp Engel, fdai7057*/
+
+char *stringConcatenation(char *string_1, char *string_2)
+{
+	int lengthStringOne = strlen(string_1);
+	int lengthStringTwo = strlen(string_2);
+	
+	if(lengthStringOne==0||lengthStringTwo==0){
+		printf("Empty strings are not allowed. Aborting.\n");
+		exit(-1);
+		//call error();
+	}
+	
+	const int totalLength = lengthStringOne + lengthStringTwo + 1;
+	char *result = calloc(totalLength, sizeof(char));
+	int i,j;
+	for(i=0,j=0;i<totalLength;++i){
+		if(i<lengthStringOne){
+			*(result+i) = *(string_1+i);
+		}else{
+			*(result+i) = *(string_2+j);
+			++j;
+		}
+	}
+	*(result+i) = '\0';
+	return result;
+}
+
+
+char *to_string(int number)
+{
+	if(number==0)
+	{
+		char *str = calloc(2,sizeof(char));
+		*(str) = '0';
+		*(str+1) = '\0';
+		return str;
+	}
+	else
+	{
+		int cpy = number, len = 0;
+		while(number>0){
+		++len;
+		number /= 10;
+		}
+		char *str = calloc(len+1, sizeof(char));
+		for(int i=0,j=len-1;i<len;++i,--j){
+		*(str+j) = '0' + (cpy % 10);
+		cpy /= 10;
+	}
+	*(str+len) = '\0';
+	return str;
+	}
+}
+
+char *generateCheckString(int customerID, char *customerPassword)
+{
+	char *IDString = to_string(customerID);
+	int IDLength = strlen(IDString);
+	int passwordLength = strlen(customerPassword);
+	int checkStringLength = IDLength + 1 + passwordLength + 1;
+	char *checkString = calloc(checkStringLength, sizeof(char));
+	checkString = strcat(IDString, "=");
+	checkString = strcat(checkString, customerPassword);
+	*(checkString+checkStringLength) = '\0';
+	return checkString;
+}
diff --git a/src/StringManipulation.h b/src/StringManipulation.h
new file mode 100644
index 0000000..a74a93c
--- /dev/null
+++ b/src/StringManipulation.h
@@ -0,0 +1,6 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+char *stringConcatenation(char *, char *);
+char *to_string(int);
+char *generateCheckString(int, char *);
diff --git a/src/docs.txt b/src/docs.txt
new file mode 100644
index 0000000..c76de12
--- /dev/null
+++ b/src/docs.txt
@@ -0,0 +1,14 @@
+char *stringConcatenation(char string_1*, char string_2*):
+
+This function takes two char pointers. In this function a new string is created. This new string is the concatenation of string_1 and string_2. The size of the new string is the length of string_1 plus the length of string_2 plus one for '\0'. This function is needed when creating an unique check string for a customer.
+
+char *to_string(int number):
+
+This function takes an integer variable as its argument. It returns an string that contains the digits of number. For example to_string(176) would return "176\0". This function is needed to write data in form of characters into the customer file. 
+
+
+char *generateCheckString(int customerID, char *password): 
+
+The purpose of this function is to generate a string that is needed when a user wants to login. This string is searched for in the customer-data file and if it is found, the login is successful. This function is needed when a new user is created because then it is written in the file for the first time. 
+The format of the returned string is [ID]=[PASSWORD]. 
+For example generateCheckString(177,"tree") would return "177=tree\0".
diff --git a/tests/build/test/cache/test_StringManipulation.c b/tests/build/test/cache/test_StringManipulation.c
new file mode 100644
index 0000000..0d87c99
--- /dev/null
+++ b/tests/build/test/cache/test_StringManipulation.c
@@ -0,0 +1,195 @@
+#include "Semester/ProgMeth/Bankmanagement/bankmanagement-system/src/StringManipulation.h"
+#include "/var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h"
+
+
+
+
+
+
+void test_to_string()
+
+{
+
+
+
+ char *result_1[] = {"0","1","2","3","4","5","6","7","8","9","10"};
+
+ char *result_2[] = {"500","502","504","506","508","510","512","514","516","518"};
+
+ char *result_3[] = {"1000","2000","3000","4000","5000","6000","7000","8000","9000","10000"};
+
+ char *result_4[] = {"9999","8999","7999","6999","5999","4999","3999","2999","1999","999"};
+
+ char *result_5[] = {"1000000","2000000","3000000","4000000","5000000","6000000","7000000",
+
+       "8000000","9000000","10000000"};
+
+
+
+ for(int i=0;i<=10;++i){
+
+  UnityAssertEqualString((const char*)((result_1[i])), (const char*)((to_string(i))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(17));
+
+ }
+
+
+
+ for(int i=0, j=500;i<10;++i,j+=2){
+
+  UnityAssertEqualString((const char*)((result_2[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(21));
+
+ }
+
+
+
+ for(int i=0, j=1000;i<10;++i,j+=1000){
+
+  UnityAssertEqualString((const char*)((result_3[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(25));
+
+ }
+
+
+
+ for(int i=0, j=9999;i<10;++i,j-=1000){
+
+  UnityAssertEqualString((const char*)((result_4[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(29));
+
+ }
+
+ for(int i=0, j=1000000;i<10;++i,j+=1000000){
+
+  UnityAssertEqualString((const char*)((result_5[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(32));
+
+ }
+
+
+
+}
+
+
+
+
+
+void test_generateCheckString()
+
+{
+
+
+
+ int numbers_1[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25};
+
+ char *strings_1[] = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
+
+ char *result_1[] = {"0=a","1=b","2=c","3=d","4=e","5=f","6=g","7=h","8=i","9=j","10=k","11=l","12=m","13=n","14=o","15=p","16=q","17=r", "18=s","19=t","20=u","21=v","22=w","23=x","24=y","25=z"};
+
+ for(int i=0;i<26;++i){
+
+  UnityAssertEqualString((const char*)((result_1[i])), (const char*)((generateCheckString(numbers_1[i],*(strings_1+i)))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(45));
+
+ }
+
+
+
+ int numbers_2[] = {0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025};
+
+ char *strings_2[] = {"z","zy","zyx","zyxw","zyxwv","zyxwvu","zyxwvut","zyxwvuts","zyxwvutsr","zyxwvutsrq","zyxwvutsrqp",
+
+        "zyxwvutsrqpo","zyxwvutsrqpon","zyxwvutsrqponm","zyxwvutsrqponml","zyxwvutsrqponmlk",
+
+        "zyxwvutsrqponmlkj","zyxwvutsrqponmlkji","zyxwvutsrqponmlkjih","zyxwvutsrqponmlkjihg","zyxwvutsrqponmlkjihgf",
+
+         "zyxwvutsrqponmlkjihgfe","zyxwvutsrqponmlkjihgfed","zyxwvutsrqponmlkjihgfedc","zyxwvutsrqponmlkjihgfedcb",
+
+         "zyxwvutsrqponmlkjihgfedcba"};
+
+ char *result_2[] = {"0=z","1=zy","1=zyx","2=zyxw","3=zyxwv","5=zyxwvu","8=zyxwvut","13=zyxwvuts","21=zyxwvutsr","34=zyxwvutsrq",
+
+                     "55=zyxwvutsrqp","89=zyxwvutsrqpo","144=zyxwvutsrqpon","233=zyxwvutsrqponm","377=zyxwvutsrqponml",
+
+       "610=zyxwvutsrqponmlk","987=zyxwvutsrqponmlkj","1597=zyxwvutsrqponmlkji","2584=zyxwvutsrqponmlkjih",
+
+       "4181=zyxwvutsrqponmlkjihg","6765=zyxwvutsrqponmlkjihgf","10946=zyxwvutsrqponmlkjihgfe",
+
+       "17711=zyxwvutsrqponmlkjihgfed","28657=zyxwvutsrqponmlkjihgfedc","46368=zyxwvutsrqponmlkjihgfedcb",
+
+       "75025=zyxwvutsrqponmlkjihgfedcba"};
+
+ for(int i=0;i<26;++i){
+
+  UnityAssertEqualString((const char*)((result_2[i])), (const char*)((generateCheckString(numbers_2[i],*(strings_2+i)))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(61));
+
+ }
+
+
+
+ srand(time(0));
+
+ int random_number=0;
+
+ char *random_numbers_strings[20];
+
+ int random_numbers[20];
+
+ for(int i=0;i<20;++i){
+
+  random_number = (rand() % 100) + 1;
+
+  random_numbers_strings[i] = to_string(random_number);
+
+  random_numbers[i] = random_number;
+
+ }
+
+ char *strings_3[] = {"tree","plant","tea","programming","assembler","unix","BSD","snow","mountain","table","wood","forest", "calculator","book","light","keyboard","old","paper","pencil","voltage"};
+
+ char *result_3[20];
+
+ for(int i=0;i<20;++i){
+
+  random_numbers_strings[i] = strcat(random_numbers_strings[i],"=");
+
+  result_3[i] = strcat(random_numbers_strings[i],strings_3[i]);
+
+  printf("%s\n",result_3[i]);
+
+ }
+
+ for(int i=0;i<20;++i){
+
+  UnityAssertEqualString((const char*)((result_3[i])), (const char*)((generateCheckString(random_numbers[i],strings_3[i]))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(81));
+
+ }
+
+}
diff --git a/tests/build/test/dependencies/StringManipulation.d b/tests/build/test/dependencies/StringManipulation.d
new file mode 100644
index 0000000..625c690
--- /dev/null
+++ b/tests/build/test/dependencies/StringManipulation.d
@@ -0,0 +1,3 @@
+build/test/out/c/StringManipulation.o: \
+ /home/julius/Documents/Studium/Informatik/1.\ Semester/ProgMeth/Bankmanagement/bankmanagement-system/src/StringManipulation.c \
+ /home/julius/Documents/Studium/Informatik/1.\ Semester/ProgMeth/Bankmanagement/bankmanagement-system/src/StringManipulation.h
diff --git a/tests/build/test/dependencies/test_StringManipulation.d b/tests/build/test/dependencies/test_StringManipulation.d
new file mode 100644
index 0000000..2f65b3c
--- /dev/null
+++ b/tests/build/test/dependencies/test_StringManipulation.d
@@ -0,0 +1,5 @@
+build/test/out/c/test_StringManipulation.o: \
+ test/test_StringManipulation.c \
+ /var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h \
+ /var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity_internals.h \
+ /home/julius/Documents/Studium/Informatik/1.\ Semester/ProgMeth/Bankmanagement/bankmanagement-system/src/StringManipulation.h
diff --git a/tests/build/test/dependencies/test_StringManipulation_runner.d b/tests/build/test/dependencies/test_StringManipulation_runner.d
new file mode 100644
index 0000000..c54fbb6
--- /dev/null
+++ b/tests/build/test/dependencies/test_StringManipulation_runner.d
@@ -0,0 +1,4 @@
+build/test/out/c/test_StringManipulation_runner.o: \
+ build/test/runners/test_StringManipulation_runner.c \
+ /var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h \
+ /var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity_internals.h
diff --git a/tests/build/test/out/c/StringManipulation.o b/tests/build/test/out/c/StringManipulation.o
new file mode 100644
index 0000000..531a498
Binary files /dev/null and b/tests/build/test/out/c/StringManipulation.o differ
diff --git a/tests/build/test/out/c/test_StringManipulation.o b/tests/build/test/out/c/test_StringManipulation.o
new file mode 100644
index 0000000..4e6507a
Binary files /dev/null and b/tests/build/test/out/c/test_StringManipulation.o differ
diff --git a/tests/build/test/out/c/test_StringManipulation_runner.o b/tests/build/test/out/c/test_StringManipulation_runner.o
new file mode 100644
index 0000000..a16f5ca
Binary files /dev/null and b/tests/build/test/out/c/test_StringManipulation_runner.o differ
diff --git a/tests/build/test/out/test_StringManipulation.out b/tests/build/test/out/test_StringManipulation.out
new file mode 100755
index 0000000..e8425d0
Binary files /dev/null and b/tests/build/test/out/test_StringManipulation.out differ
diff --git a/tests/build/test/preprocess/files/test_StringManipulation.c b/tests/build/test/preprocess/files/test_StringManipulation.c
new file mode 100644
index 0000000..0d87c99
--- /dev/null
+++ b/tests/build/test/preprocess/files/test_StringManipulation.c
@@ -0,0 +1,195 @@
+#include "Semester/ProgMeth/Bankmanagement/bankmanagement-system/src/StringManipulation.h"
+#include "/var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h"
+
+
+
+
+
+
+void test_to_string()
+
+{
+
+
+
+ char *result_1[] = {"0","1","2","3","4","5","6","7","8","9","10"};
+
+ char *result_2[] = {"500","502","504","506","508","510","512","514","516","518"};
+
+ char *result_3[] = {"1000","2000","3000","4000","5000","6000","7000","8000","9000","10000"};
+
+ char *result_4[] = {"9999","8999","7999","6999","5999","4999","3999","2999","1999","999"};
+
+ char *result_5[] = {"1000000","2000000","3000000","4000000","5000000","6000000","7000000",
+
+       "8000000","9000000","10000000"};
+
+
+
+ for(int i=0;i<=10;++i){
+
+  UnityAssertEqualString((const char*)((result_1[i])), (const char*)((to_string(i))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(17));
+
+ }
+
+
+
+ for(int i=0, j=500;i<10;++i,j+=2){
+
+  UnityAssertEqualString((const char*)((result_2[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(21));
+
+ }
+
+
+
+ for(int i=0, j=1000;i<10;++i,j+=1000){
+
+  UnityAssertEqualString((const char*)((result_3[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(25));
+
+ }
+
+
+
+ for(int i=0, j=9999;i<10;++i,j-=1000){
+
+  UnityAssertEqualString((const char*)((result_4[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(29));
+
+ }
+
+ for(int i=0, j=1000000;i<10;++i,j+=1000000){
+
+  UnityAssertEqualString((const char*)((result_5[i])), (const char*)((to_string(j))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(32));
+
+ }
+
+
+
+}
+
+
+
+
+
+void test_generateCheckString()
+
+{
+
+
+
+ int numbers_1[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25};
+
+ char *strings_1[] = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
+
+ char *result_1[] = {"0=a","1=b","2=c","3=d","4=e","5=f","6=g","7=h","8=i","9=j","10=k","11=l","12=m","13=n","14=o","15=p","16=q","17=r", "18=s","19=t","20=u","21=v","22=w","23=x","24=y","25=z"};
+
+ for(int i=0;i<26;++i){
+
+  UnityAssertEqualString((const char*)((result_1[i])), (const char*)((generateCheckString(numbers_1[i],*(strings_1+i)))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(45));
+
+ }
+
+
+
+ int numbers_2[] = {0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025};
+
+ char *strings_2[] = {"z","zy","zyx","zyxw","zyxwv","zyxwvu","zyxwvut","zyxwvuts","zyxwvutsr","zyxwvutsrq","zyxwvutsrqp",
+
+        "zyxwvutsrqpo","zyxwvutsrqpon","zyxwvutsrqponm","zyxwvutsrqponml","zyxwvutsrqponmlk",
+
+        "zyxwvutsrqponmlkj","zyxwvutsrqponmlkji","zyxwvutsrqponmlkjih","zyxwvutsrqponmlkjihg","zyxwvutsrqponmlkjihgf",
+
+         "zyxwvutsrqponmlkjihgfe","zyxwvutsrqponmlkjihgfed","zyxwvutsrqponmlkjihgfedc","zyxwvutsrqponmlkjihgfedcb",
+
+         "zyxwvutsrqponmlkjihgfedcba"};
+
+ char *result_2[] = {"0=z","1=zy","1=zyx","2=zyxw","3=zyxwv","5=zyxwvu","8=zyxwvut","13=zyxwvuts","21=zyxwvutsr","34=zyxwvutsrq",
+
+                     "55=zyxwvutsrqp","89=zyxwvutsrqpo","144=zyxwvutsrqpon","233=zyxwvutsrqponm","377=zyxwvutsrqponml",
+
+       "610=zyxwvutsrqponmlk","987=zyxwvutsrqponmlkj","1597=zyxwvutsrqponmlkji","2584=zyxwvutsrqponmlkjih",
+
+       "4181=zyxwvutsrqponmlkjihg","6765=zyxwvutsrqponmlkjihgf","10946=zyxwvutsrqponmlkjihgfe",
+
+       "17711=zyxwvutsrqponmlkjihgfed","28657=zyxwvutsrqponmlkjihgfedc","46368=zyxwvutsrqponmlkjihgfedcb",
+
+       "75025=zyxwvutsrqponmlkjihgfedcba"};
+
+ for(int i=0;i<26;++i){
+
+  UnityAssertEqualString((const char*)((result_2[i])), (const char*)((generateCheckString(numbers_2[i],*(strings_2+i)))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(61));
+
+ }
+
+
+
+ srand(time(0));
+
+ int random_number=0;
+
+ char *random_numbers_strings[20];
+
+ int random_numbers[20];
+
+ for(int i=0;i<20;++i){
+
+  random_number = (rand() % 100) + 1;
+
+  random_numbers_strings[i] = to_string(random_number);
+
+  random_numbers[i] = random_number;
+
+ }
+
+ char *strings_3[] = {"tree","plant","tea","programming","assembler","unix","BSD","snow","mountain","table","wood","forest", "calculator","book","light","keyboard","old","paper","pencil","voltage"};
+
+ char *result_3[20];
+
+ for(int i=0;i<20;++i){
+
+  random_numbers_strings[i] = strcat(random_numbers_strings[i],"=");
+
+  result_3[i] = strcat(random_numbers_strings[i],strings_3[i]);
+
+  printf("%s\n",result_3[i]);
+
+ }
+
+ for(int i=0;i<20;++i){
+
+  UnityAssertEqualString((const char*)((result_3[i])), (const char*)((generateCheckString(random_numbers[i],strings_3[i]))), (
+
+ ((void *)0)
+
+ ), (UNITY_UINT)(81));
+
+ }
+
+}
diff --git a/tests/build/test/preprocess/includes/test_StringManipulation.c b/tests/build/test/preprocess/includes/test_StringManipulation.c
new file mode 100644
index 0000000..77ded96
--- /dev/null
+++ b/tests/build/test/preprocess/includes/test_StringManipulation.c
@@ -0,0 +1,3 @@
+---
+- "/var/lib/gems/2.7.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h"
+- Semester/ProgMeth/Bankmanagement/bankmanagement-system/src/StringManipulation.h
diff --git a/tests/build/test/results/test_StringManipulation.pass b/tests/build/test/results/test_StringManipulation.pass
new file mode 100644
index 0000000..84a7b10
--- /dev/null
+++ b/tests/build/test/results/test_StringManipulation.pass
@@ -0,0 +1,42 @@
+---
+:source:
+  :path: test
+  :file: test_StringManipulation.c
+:successes:
+- :test: test_to_string
+  :line: 6
+  :message: ''
+  :unity_test_time: 0
+- :test: test_generateCheckString
+  :line: 38
+  :message: ''
+  :unity_test_time: 0
+:failures: []
+:ignores: []
+:counts:
+  :total: 2
+  :passed: 2
+  :failed: 0
+  :ignored: 0
+:stdout:
+- 9=tree
+- 26=plant
+- 92=tea
+- 31=programming
+- 75=assembler
+- 28=unix
+- 92=BSD
+- 99=snow
+- 10=mountain
+- 43=table
+- 92=wood
+- 98=forest
+- 3=calculator
+- 32=book
+- 29=light
+- 92=keyboard
+- 35=old
+- 27=paper
+- 85=pencil
+- 91=voltage
+:time: 0.0019293400000606198
diff --git a/tests/build/test/runners/test_StringManipulation_runner.c b/tests/build/test/runners/test_StringManipulation_runner.c
new file mode 100644
index 0000000..8c93227
--- /dev/null
+++ b/tests/build/test/runners/test_StringManipulation_runner.c
@@ -0,0 +1,89 @@
+/* AUTOGENERATED FILE. DO NOT EDIT. */
+
+/*=======Automagically Detected Files To Include=====*/
+#include "unity.h"
+
+int GlobalExpectCount;
+int GlobalVerifyOrder;
+char* GlobalOrderError;
+
+/*=======External Functions This Runner Calls=====*/
+extern void setUp(void);
+extern void tearDown(void);
+extern void test_to_string();
+extern void test_generateCheckString();
+
+
+/*=======Mock Management=====*/
+static void CMock_Init(void)
+{
+  GlobalExpectCount = 0;
+  GlobalVerifyOrder = 0;
+  GlobalOrderError = NULL;
+}
+static void CMock_Verify(void)
+{
+}
+static void CMock_Destroy(void)
+{
+}
+
+/*=======Setup (stub)=====*/
+void setUp(void) {}
+
+/*=======Teardown (stub)=====*/
+void tearDown(void) {}
+
+/*=======Test Reset Options=====*/
+void resetTest(void);
+void resetTest(void)
+{
+  tearDown();
+  CMock_Verify();
+  CMock_Destroy();
+  CMock_Init();
+  setUp();
+}
+void verifyTest(void);
+void verifyTest(void)
+{
+  CMock_Verify();
+}
+
+/*=======Test Runner Used To Run Each Test=====*/
+static void run_test(UnityTestFunction func, const char* name, UNITY_LINE_TYPE line_num)
+{
+    Unity.CurrentTestName = name;
+    Unity.CurrentTestLineNumber = line_num;
+#ifdef UNITY_USE_COMMAND_LINE_ARGS
+    if (!UnityTestMatches())
+        return;
+#endif
+    Unity.NumberOfTests++;
+    UNITY_CLR_DETAILS();
+    UNITY_EXEC_TIME_START();
+    CMock_Init();
+    if (TEST_PROTECT())
+    {
+        setUp();
+        func();
+    }
+    if (TEST_PROTECT())
+    {
+        tearDown();
+        CMock_Verify();
+    }
+    CMock_Destroy();
+    UNITY_EXEC_TIME_STOP();
+    UnityConcludeTest();
+}
+
+/*=======MAIN=====*/
+int main(void)
+{
+  UnityBegin("test_StringManipulation.c");
+  run_test(test_to_string, "test_to_string", 6);
+  run_test(test_generateCheckString, "test_generateCheckString", 38);
+
+  return UnityEnd();
+}
diff --git a/tests/test/test_StringManipulation.c b/tests/test/test_StringManipulation.c
new file mode 100644
index 0000000..accd414
--- /dev/null
+++ b/tests/test/test_StringManipulation.c
@@ -0,0 +1,83 @@
+#include "unity.h"
+#include "StringManipulation.h"
+#include <time.h>
+#include <string.h>
+
+void test_to_string() 
+{
+	/*initializing test values*/
+	char *result_1[] = {"0","1","2","3","4","5","6","7","8","9","10"};
+	char *result_2[] = {"500","502","504","506","508","510","512","514","516","518"};
+	char *result_3[] = {"1000","2000","3000","4000","5000","6000","7000","8000","9000","10000"};
+	char *result_4[] = {"9999","8999","7999","6999","5999","4999","3999","2999","1999","999"};
+	char *result_5[] = {"1000000","2000000","3000000","4000000","5000000","6000000","7000000",
+			    "8000000","9000000","10000000"};
+
+	for(int i=0;i<=10;++i){
+		TEST_ASSERT_EQUAL_STRING(result_1[i],to_string(i));
+	}	
+	
+	for(int i=0, j=500;i<10;++i,j+=2){
+		TEST_ASSERT_EQUAL_STRING(result_2[i],to_string(j));
+	}
+
+	for(int i=0, j=1000;i<10;++i,j+=1000){
+		TEST_ASSERT_EQUAL_STRING(result_3[i],to_string(j));	
+	}
+	
+	for(int i=0, j=9999;i<10;++i,j-=1000){
+		TEST_ASSERT_EQUAL_STRING(result_4[i], to_string(j));
+	}
+	for(int i=0, j=1000000;i<10;++i,j+=1000000){
+		TEST_ASSERT_EQUAL_STRING(result_5[i],to_string(j));
+	}
+
+}
+
+
+void test_generateCheckString() 
+{
+	/*test block 1*/
+	int numbers_1[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25};
+	char *strings_1[] = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
+	char *result_1[] = {"0=a","1=b","2=c","3=d","4=e","5=f","6=g","7=h","8=i","9=j","10=k","11=l","12=m","13=n","14=o","15=p","16=q","17=r",                            "18=s","19=t","20=u","21=v","22=w","23=x","24=y","25=z"};
+	for(int i=0;i<26;++i){
+		TEST_ASSERT_EQUAL_STRING(result_1[i],generateCheckString(numbers_1[i],*(strings_1+i)));
+	}
+	/*test block 2*/
+	int numbers_2[] = {0,1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025};
+	char *strings_2[] = {"z","zy","zyx","zyxw","zyxwv","zyxwvu","zyxwvut","zyxwvuts","zyxwvutsr","zyxwvutsrq","zyxwvutsrqp",
+			     "zyxwvutsrqpo","zyxwvutsrqpon","zyxwvutsrqponm","zyxwvutsrqponml","zyxwvutsrqponmlk",
+			     "zyxwvutsrqponmlkj","zyxwvutsrqponmlkji","zyxwvutsrqponmlkjih","zyxwvutsrqponmlkjihg","zyxwvutsrqponmlkjihgf",
+			      "zyxwvutsrqponmlkjihgfe","zyxwvutsrqponmlkjihgfed","zyxwvutsrqponmlkjihgfedc","zyxwvutsrqponmlkjihgfedcb",
+			      "zyxwvutsrqponmlkjihgfedcba"};
+	char *result_2[] = {"0=z","1=zy","1=zyx","2=zyxw","3=zyxwv","5=zyxwvu","8=zyxwvut","13=zyxwvuts","21=zyxwvutsr","34=zyxwvutsrq",
+	                    "55=zyxwvutsrqp","89=zyxwvutsrqpo","144=zyxwvutsrqpon","233=zyxwvutsrqponm","377=zyxwvutsrqponml",
+			    "610=zyxwvutsrqponmlk","987=zyxwvutsrqponmlkj","1597=zyxwvutsrqponmlkji","2584=zyxwvutsrqponmlkjih",
+			    "4181=zyxwvutsrqponmlkjihg","6765=zyxwvutsrqponmlkjihgf","10946=zyxwvutsrqponmlkjihgfe",
+			    "17711=zyxwvutsrqponmlkjihgfed","28657=zyxwvutsrqponmlkjihgfedc","46368=zyxwvutsrqponmlkjihgfedcb",
+			    "75025=zyxwvutsrqponmlkjihgfedcba"};
+	for(int i=0;i<26;++i){
+		TEST_ASSERT_EQUAL_STRING(result_2[i],generateCheckString(numbers_2[i],*(strings_2+i)));	
+	}
+	/*test block 3*/
+	srand(time(0));
+	int random_number=0;
+	char *random_numbers_strings[20];
+	int random_numbers[20];
+	for(int i=0;i<20;++i){
+		random_number = (rand() % 100) + 1;
+		random_numbers_strings[i] = to_string(random_number);
+		random_numbers[i] = random_number;
+	}
+	char *strings_3[] = {"tree","plant","tea","programming","assembler","unix","BSD","snow","mountain","table","wood","forest", "calculator","book","light","keyboard","old","paper","pencil","voltage"};
+	char *result_3[20];
+	for(int i=0;i<20;++i){
+		random_numbers_strings[i] = strcat(random_numbers_strings[i],"=");
+		result_3[i] = strcat(random_numbers_strings[i],strings_3[i]);
+		printf("%s\n",result_3[i]);
+	}
+	for(int i=0;i<20;++i){
+		TEST_ASSERT_EQUAL_STRING(result_3[i],generateCheckString(random_numbers[i],strings_3[i]));
+	}
+}