A very basic Clojure tutorial for those who want to get introduced to Clojure. I recommend using Light Table IDE for coding Clojure. [http://www.lighttable.com/ ]

clojure-basic-tutorial.clj

;-----------------------------------------------------------------------------------
; 1 - example of simple operations
;-----------------------------------------------------------------------------------
; arithmatic operations
(+ 1 2)
(* 2 3)
(/ 8 2)
(> 4 3)
(= 4 6)

; conditions
(if true  "true" "false")
(if false "true" "false")
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 2 - example of using java functions
;-----------------------------------------------------------------------------------
; using function with members of Int class
(.toString 2)

; using function with members of String class
(.length "I am text!")

; create new object of Random class
(new java.util.Random)

; create new object of Random class and save it in a variable
(def rnd (new java.util.Random))

; call a method inside the object instance using (.)
(. rnd nextInt)

; call a method inside the object instance using (.) with passing arguments
(. rnd nextInt 10)
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 3 - example of nested defined functions and call example
;-----------------------------------------------------------------------------------
; define a function that uses if and else condition
(defn get-tax-ratio [salary] (if (> salary 1000) 0.35 0.1 ))

; define a function that uses another defined function inside it
(defn get-tax-value [salary] (* (get-tax-ratio salary) salary))

; cal a function with a parameter
(get-tax-value 1000)
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 4 - example of creating  maps
;-----------------------------------------------------------------------------------
; defining a new map
(def inventors {"Lisp" "McCarthy", "Clojure" "Hickey"})

;looking up for value with the map key
(inventors "Lisp"   )
(inventors "Clojure")

;looking up for map values in the map with default value for nil results
(get inventors "Lisp" "Not Found 404!")
(get inventors "C++"  "Not Found 404!")
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 5 - example of using keyword
;-----------------------------------------------------------------------------------
; define a map using keywords
(def school {:field "Computer Science" :place "Cairo"})

; get value from a data structure using keywords as a function that look up itself
(:field school)

;get a value of keyword using simple look up by the map key
(school :field)
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 6 - example of creating records
;-----------------------------------------------------------------------------------
; defining a new record structure called book with keywords [title author field]
(defrecord Book [title author field])

; defining a new instance of the book record
(def binstance (->Book "AlgorithmsBook" "Al-Khawarzmi" "Mathematics"))

; get the value of the book instance
binstance

; getting the keywords values if the instance b-instance of the book record
(:title  binstance)
(:author binstance)
(:field  binstance)

; create an instance of Book record on the fly
(Book. "Networks" "Alan" "Information Technology")
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 7 - example of using let binding
;-----------------------------------------------------------------------------------
; bind sequence to the relative variables [x <- 1 , y <- 2] and 3 is not used
(let [[x y] [1 2 3]]
  (+ x y)
)

; bind with let and use the '_' neglect character which also take right most value
(let [[_ _ y] [1 7 3]]
  (+ _ y)
)
;***********************************************************************************



;-----------------------------------------------------------------------------------
; 8 - example of using for binding
;-----------------------------------------------------------------------------------
; using simple for binding for a var 'x' as '[3 4 6]'
(for [x [3 4 6]] ; the binding part 
  (* x 2)        ; the body part    s
)

; use for binding for two vars 'x' 'y' as ranges and eval all possible combinations
(for [x (range 1 4), y (range 2 5)] ; the binding part 
  (+ x y)                           ; the body part    
)
;***********************************************************************************

clojure-swing-gui-tutorial.clj

; clojure gui demo for sum two numbers using java swing 

(import '(javax.swing    JFrame JLabel JTextField JButton )
        '(java.awt.event ActionListener                   )
        '(java.awt       GridLayout                       )
)

(defn sum-two-num-gui-demo []
  (let 
    ; =================================================================
    ; Binding Header - Components declaration
    ; =================================================================
    [ frame            (JFrame.     "Sum two numbers"  )
         
      num1-text        (JTextField.                    )
      num2-text        (JTextField.                    )
         
      first-label      (JLabel.     "First num"        )
      second-label     (JLabel.     "Second num"       )
      
      sum-button       (JButton.    "Sum"              )
    ]
    
    ; =================================================================
    ; Binding Body
    ; =================================================================
    
    ; -----------------------------------------------------------------    
    ; add action event to the sum-button
    (.addActionListener sum-button
      (reify ActionListener
            (actionPerformed
             [_ evt]
             (let [
                     num1 (Double/parseDouble (.getText num1-text)),
                     num2 (Double/parseDouble (.getText num2-text))
                  ]
               
               (javax.swing.JOptionPane/showMessageDialog nil (str "Result:" (+ num1 num2)))
             )
            )
      )
    )
    
    ; -----------------------------------------------------------------
    ; configure num1-text properties
    (doto num1-text
      (.setBounds 100 15 200 25)
    )
    
    ; -----------------------------------------------------------------
    ; configure num1-text properties
    (doto num2-text
      (.setBounds 100 45 200 25)
    )
    
    ; -----------------------------------------------------------------
    ; configure sum-buton properties
    (doto sum-button
      (.setBounds 100 80 200 30)
    )
    
    ; -----------------------------------------------------------------
    ; configure first-label properties
    (doto first-label
      (.setBounds 10 10 100 25)
    )
    ; -----------------------------------------------------------------
    ; configure second-label properties
    (doto second-label
      (.setBounds 10 45 100 25) 
    )
    
    ; -----------------------------------------------------------------
    ; configure the frame properties
    (doto frame      
      (.setLayout    nil      )
      
      ; add gui component to frame object
      (.add num1-text    )
      (.add num2-text    )
      (.add first-label  )
      (.add second-label )      
      (.add sum-button   )      
        
      ; adjust frame properties
      (.setSize      350 150  )
      (.setResizable false    )
      (.setVisible   true     )      
      
    )
    ; -----------------------------------------------------------------
  )
)

(sum-two-num-gui-demo)