diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..99e1e0e
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diff --git a/Belal Dohal Exame.playground/Contents.swift b/Belal Dohal Exame.playground/Contents.swift
new file mode 100644
index 0000000..15997ee
--- /dev/null
+++ b/Belal Dohal Exame.playground/Contents.swift	
@@ -0,0 +1,39 @@
+// MARK: Belal Ahmad Dohal
+// Swift
+
+//Q1).Create a function that receives an integers array and returns the number that appeared only once.
+func getOnlyOneNumber(arr:[Int]) -> [Int] {
+    var singleNumbers = [Int:Int]()
+    var result = [Int]()
+    for i in arr {
+        singleNumbers[i] = i
+    }
+    for i in singleNumbers {
+        result.append(i.key)
+    }
+    return result
+}
+//Q2).Create a function that receives a string then it converts uppercase letters into lowercase and vice versa. The function then should print the converted value.
+func printConvertString(str:String) {
+    var result = ""
+    for i in str {
+        if i.isLowercase == true {
+            result += i.uppercased()
+        }else {
+            result += i.uppercased()
+        }
+    }
+    print(result)
+}
+//Q3).Create a function that receives an array of items & arrays and returns one flattened array with all items exluding null values.
+func noNull(arr:[Any]) -> [Any] {
+    var result = [Any]()
+    for i in arr {
+        if i == nil {
+            result.append(i)
+        }
+    }
+    return result
+}
+//Q3).Create a function that receives a string that contains combination of parentheses, square brackets, and curly braces. Then, it returns true if every opening bracket has a closing pair.
+
diff --git a/Belal Dohal Exame.playground/contents.xcplayground b/Belal Dohal Exame.playground/contents.xcplayground
new file mode 100644
index 0000000..cf026f2
--- /dev/null
+++ b/Belal Dohal Exame.playground/contents.xcplayground	
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='ios' buildActiveScheme='true' importAppTypes='true'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>
\ No newline at end of file
diff --git a/Belal Dohal Exame.playground/playground.xcworkspace/contents.xcworkspacedata b/Belal Dohal Exame.playground/playground.xcworkspace/contents.xcworkspacedata
new file mode 100644
index 0000000..ca3329e
--- /dev/null
+++ b/Belal Dohal Exame.playground/playground.xcworkspace/contents.xcworkspacedata	
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:">
+   </FileRef>
+</Workspace>
diff --git a/Belal Dohal Exame.playground/playground.xcworkspace/xcuserdata/mr_belal.xcuserdatad/UserInterfaceState.xcuserstate b/Belal Dohal Exame.playground/playground.xcworkspace/xcuserdata/mr_belal.xcuserdatad/UserInterfaceState.xcuserstate
new file mode 100644
index 0000000..00d5d23
Binary files /dev/null and b/Belal Dohal Exame.playground/playground.xcworkspace/xcuserdata/mr_belal.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/README.md b/README.md
index debb56b..92ded6e 100644
--- a/README.md
+++ b/README.md
@@ -51,3 +51,44 @@ Create a function that receives a string that contains combination of parenthese
 
 
 
+===============
+// MARK: Belal Ahmad Dohal
+// Swift
+
+//Q1).Create a function that receives an integers array and returns the number that appeared only once.
+func getOnlyOneNumber(arr:[Int]) -> [Int] {
+    var singleNumbers = [Int:Int]()
+    var result = [Int]()
+    for i in arr {
+        singleNumbers[i] = i
+    }
+    for i in singleNumbers {
+        result.append(i.key)
+    }
+    return result
+}
+//Q2).Create a function that receives a string then it converts uppercase letters into lowercase and vice versa. The function then should print the converted value.
+func printConvertString(str:String) {
+    var result = ""
+    for i in str {
+        if i.isLowercase == true {
+            result += i.uppercased()
+        }else {
+            result += i.uppercased()
+        }
+    }
+    print(result)
+}
+//Q3).Create a function that receives an array of items & arrays and returns one flattened array with all items exluding null values.
+func noNull(arr:[Any]) -> [Any] {
+    var result = [Any]()
+    for i in arr {
+        if let num = i {
+        result.append(num)
+        }
+    }
+    return result
+}
+//Q3).Create a function that receives a string that contains combination of parentheses, square brackets, and curly braces. Then, it returns true if every opening bracket has a closing pair.
+
+