Coffeescript 简明教程

name = "Raju"
console.log "Hello"+name+" Welcome to Tutorialspoint"

c:\> coffee -c sample.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var name;
  name = "Raju";
  console.log("Hello " + name + " Welcome to Tutorialspoint");

}).call(this);

c:\>coffee -o E://data sample.coffee

name = "Javed"
age = 26

name = "Javed";age = 26

# This is the single line comment in CoffeeScript

###
These are the multi line comments in CoffeeScript
We can write as many number of lines as we want
within the pair of triple hash tags.
###

name = "Javed"
age = 25

c:\> compile -c variable_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var age, name;
  name = "Javed";
  age = 25;

}).call(this);

a=21
b="21"
result = 21=='21'
console.log result

// Generated by CoffeeScript 1.10.0
(function() {
  var a, b, result;

  a = 21;

  b = "21";

  result = a === b;
  console.log(result);
}).call(this);

false

name="Ramu"
age=24
subject="Engineering"
verify_name = name?
verify_phone = phone?
console.log verify_name
console.log verify_phone

// Generated by CoffeeScript 1.10.0
(function() {
  var age, name, subject, verify_name, verify_phone;
  name = "Ramu";
  age = 24;

  subject = "Engineering";
  verify_name = name != null;
  verify_phone = typeof phone !== "undefined" && phone !== null;
  console.log(verify_name);
  console.log(verify_phone);

}).call(this);

true
false

score = 70
passed = 100 > score > 40

console.log passed

// Generated by CoffeeScript 1.10.0
(function() {
  var passed, score;

  score = 70;

  passed = (100 > score && score > 40);

  console.log(passed);

}).call(this);

true

a=21; b=21

x = true; y = false

console.log a is b

console.log a isnt b

console.log x and y

console.log x or y

console.log yes or no

console.log on or off

console.log a**b

console.log a//b

console.log a%%b

// Generated by CoffeeScript 1.10.0
(function() {
  var a, b, x, y,
    modulo = function(a, b) { return (+a % (b = +b) + b) % b; };

  a = 21;

  b = 21;

  x = true;

  y = false;

  console.log(a === b);

  console.log(a !== b);

  console.log(x && y);

  console.log(x || y);

  console.log(true || false);

  console.log(true || false);

  console.log(Math.pow(a, b));

  console.log(Math.floor(a / b));

  console.log(modulo(a, b));

}).call(this);

true
false
false
true
true
true
5.842587018385982e+27
1
0

while expression
   statements to be executed

console.log "Starting Loop "
count = 0
while count < 10
   console.log "Current Count : " + count
   count++;

console.log "Set the variable to different value and then try"

c:\> coffee -c while_loop_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var count;

  console.log("Starting Loop ");

  count = 0;

  while (count < 10) {
    console.log("Current Count : " + count);
    count++;
  }

  console.log("Set the variable to different value and then try");

}).call(this);

c:\> coffee while_loop_example.coffee

Starting Loop
Current Count : 0
Current Count : 1
Current Count : 2
Current Count : 3
Current Count : 4
Current Count : 5
Current Count : 6
Current Count : 7
Current Count : 8
Current Count : 9
Set the variable to different value and then try

for student,i in ['Ram', 'Mohammed', 'John']
   console.log "The name of the student with id "+i+" is: "+student

c:\> coffee -c for_in_index.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var i, j, len, ref, student;

  ref = ['Ram', 'Mohammed', 'John'];
  for (i = j = 0, len = ref.length; j < len; i = ++j) {
    student = ref[i];
    console.log("The name of the student with id " + i + " is: " + student);
  }
}).call(this);

c:\> coffee for_in_index.coffee

The name of the student with id 0 is: Ram
The name of the student with id 1 is: Mohammed
The name of the student with id 2 is: John

my_function =->
   student = ['Ram', 'Mohammed', 'John']

   #Assigning comprehension to a variable
   names = (x for x in student )
   console.log "The contents of the variable names are ::"+names

   #Returning the comprehension
   return x for x in student
console.log "The value returned by the function is "+my_function()

c:\> coffee -c example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var my_function;

  my_function = function() {
    var i, len, names, student, x;
    student = ['Ram', 'Mohammed', 'John'];
    names = (function() {
      var i, len, results;
      results = [];
      for (i = 0, len = student.length; i < len; i++) {
        x = student[i];
        results.push(x);
      }
      return results;
    })();
    console.log("The contents of the variable names are ::" + names);
    for (i = 0, len = student.length; i < len; i++) {
      x = student[i];
      return x;
    }
  };

  console.log("The value returned by the function is " + my_function());

}).call(this);

c:\> coffee example.coffee

The contents of the variable names are ::Ram,Mohammed,John
The value returned by the function is Ram

array = (num for num in [1..10] by 2)
console.log array

c:\> coffee -c by_keyword_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var array, num;

  array = (function() {
    var i, results;
    results = [];
    for (num = i = 1; i <= 10; num = i += 2) {
      results.push(num);
    }
    return results;
  })();

  console.log(array);

}).call(this);

c:\> coffee by_keyword_example.coffee

[ 1, 3, 5, 7, 9 ]

greet = -> "This is an example of a function"

c:\>coffee -c function_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var greet;

  greet = function() {
    return "This is an example of a function";
  };

}).call(this);

students = [ "Rahman", "Ramu", "Ravi", "Robert" ]
console.log student for student in students

c:\> coffee -c array_comprehensions.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var i, len, student, students;

  students = ["Rahman", "Ramu", "Ravi", "Robert"];

  for (i = 0, len = students.length; i − len; i++) {
    student = students[i];
    console.log(student);
  }

}).call(this);

c:\> coffee array_comprehensions.coffee

Rahman
Ramu
Ravi
Robert

students = [ "Rahman", "Ramu", "Ravi", "Robert",21 ]

student =
  name: "Mohammed"
  age: 24
  phone: 9848022338

contact =
  personal:
    email: "personal@gmail.com"
    phone:  9848022338
  professional:
    email: "professional@gmail.com"
    phone:  9848033228

> coffee -c nested_objects.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var contact;

  contact = {
    personal: {
      email: "personal@gmail.com",
      phone: 9848022338
    },
    professional: {
      email: "professional@gmail.com",
      phone: 9848033228
    }
  };

}).call(this);

student =
  name: "Mohammed"
  age: 24
  phone: 9848022338

console.log key+"::"+value for key,value of student

> coffee -c object_comprehensions.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var key, student, value;

  student = {
    name: "Mohammed",
    age: 24,
    phone: 9848022338
  };

  for (key in student) {
    value = student[key];
    console.log(key(+"::" + value));
  }

}).call(this);

> coffee object_comprehensions.coffee

name::Mohammed
age::24
phone::9848022338

student ={
  name: "Mohammed"
  age: 24
  phone: 9848022338
  class: "X"
  }
console.log key+"::"+value for key,value of student

c:\> coffee -c reserved_keywords.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var key, student, value;

  student = {
    name: "Mohammed",
    age: 24,
    phone: 9848022338,
    "class": "X"
  };

  for (key in student) {
    value = student[key];
    console.log(key + "::" + value);
  }

}).call(this);

c:\> coffee array_of_objects.coffee

name::Mohammed
age::24
phone::9848022338
class::X

numbers =[0...9]
console.log "The contents of the range are:: "+ numbers

c:\> coffee -c ranges_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var numbers;

  numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8];

  console.log("The contents of the range are:: " + numbers);

}).call(this);

c:\> coffee ranges_example.coffee

The contents of the range are:: 0,1,2,3,4,5,6,7,8

start=0
end=9
numbers =[start..end]
console.log "The contents of the range are: "+ numbers

c:\> coffee -c range_variables.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var end, i, numbers, results, start;

  start = 0;

  end = 9;

  numbers = (function() {
    results = [];
    for (var i = start; start <= end ? i <= end : i >= end; start <= end ? i++ : i--) {
      results.push(i);
    }
    return results;
  }).apply(this);

  console.log("The contents of the range are:: " + numbers);

}).call(this);

c:\> coffee range_variables.coffee

The contents of the range are:: 0,1,2,3,4,5,6,7,8,9

#slicing an array using ranges
num  = [1, 2, 3, 4, 5, 6, 7, 8, 9]
data = num[0..5]
console.log "The first four elements of the array : "+data


#Using negative values
data = num[-3..]
console.log "The last 3 elements of the array : "+data

#Extracting the whole array
console.log "Total elements of the array : "+num[..]


#Replacing the elements of an array
num[2..6] = [13,14,15,16,17]
console.log "New array : "+num

c:\> coffee -c range_arrays.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var data, num, ref;

  num = [1, 2, 3, 4, 5, 6, 7, 8, 9];

  data = num.slice(0, 6);

  console.log("The first four elements of the array : " + data);

  data = num.slice(-3);

  console.log("The last 3 elements of the array : " + data);

  console.log("Total elements of the array : " + num.slice(0));

  [].splice.apply(num, [2, 5].concat(ref = [13, 14, 15, 16, 17])), ref;

  console.log("New array : " + num);

}).call(this);

c:\> coffee range_arrays.coffee

The first four elements of the array : 1,2,3,4,5,6
The last 3 elements of the array : 7,8,9
Total elements of the array : 1,2,3,4,5,6,7,8,9
New array : 1,2,13,14,15,16,17,8,9

my_string = "Welcome to tutorialspoint"
new_string = my_string[0..10]
console.log new_string

c:\> coffee -c ranges_with_strings.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var my_string, new_string;

  my_string = "Welcome to tutorialspoint";

  new_string = my_string.slice(0, 6);

  console.log(new_string);

}).call(this);

c:\> coffee ranges_with_strings.coffee

Welcome to

numbers =[0..9]
console.log "The elements of the range are: "
console.log num for num in numbers

c:\> coffee -c comprehensions_over_ranges.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var i, len, num, numbers;

  numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];

  console.log("The elements of the range are: ");

  for (i = 0, len = numbers.length; i < len; i++) {
    num = numbers[i];
    console.log(num);
  }

}).call(this);

c:\> coffee comprehensions_over_ranges.coffee

The elements of the range are:
0
1
2
3
4
5
6
7
8

array = (num for num in [1..10] by 2)
console.log array

indian_team = (first, second, others...) ->
  Captain = first
  WiseCaptain = second
  team  = others
  console.log "Captain: " +Captain
  console.log "Wise captain: " +WiseCaptain
  console.log "Other team members: " +team

squad = [
   "Mahendra Singh Dhoni"
   "Virat Kohli"
   "Shikhar Dhawan"
   "Rohit Sharma"
   "Gurkeerat Singh Mann"
   "Rishi Dhawan"
   "R Ashwin"
   "Ravindra Jadeja"
   "Axar Patel"
   "Jasprit Bumrah"
   "Umesh Yadav"
   "Harbhajan Singh"
   "Ashish Nehra"
   "Hardik Pandya"
   "Suresh Raina"
   "Yuvraj Singh"
   "Ajinkya Rahane"
 ]

indian_team squad...

c:\> coffee -c splats_call.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var indian_team, squad,
    slice = [].slice;

  indian_team = function() {
    var Captain, WiseCaptain, first, others, second, team;
    first = arguments[0], second = arguments[1], others = 3 <= arguments.length ? slice.call(arguments, 2) : [];
    Captain = first;
    WiseCaptain = second;
    team = others;
    console.log("Captain: " + Captain);
    console.log("Wise captain: " + WiseCaptain);
    return console.log("Other team members: " + team);
  };

  squad = ["Mahendra Singh Dhoni", "Virat Kohli", "Shikhar Dhawan", "Rohit Sharma", "Gurkeerat Singh Mann", "Rishi Dhawan", "R Ashwin", "Ravindra Jadeja", "Axar Patel", "Jasprit Bumrah", "Umesh Yadav", "Harbhajan Singh", "Ashish Nehra", "Hardik Pandya", "Suresh Raina", "Yuvraj Singh", "Ajinkya Rahane"];

  indian_team.apply(null, squad);

}).call(this);

c:\> coffee splats_call.coffee

Captain: Mahendra Singh Dhoni
Wise captain: Virat Kohli
Other team members: Shikhar Dhawan,Rohit Sharma,Gurkeerat Singh Mann,Rishi Dhawan,R Ashwin,Ravindra Jadeja,Axar Patel,Jasprit Bumrah,Umesh Yadav,Harbhajan Singh,Ashish Nehra,Hardik Pandya,Suresh Raina,Yuvraj Singh,Ajinkya Rahane

e_value = Math.E
console.log "The value of the constant E is: " + e_value

LN2_value = Math.LN2
console.log "The value of the constant LN2 is: " + LN2_value

LN10_value = Math.LN10
console.log "The value of the constant LN10 is: " + LN10_value

LOG2E_value = Math.LOG2E
console.log "The value of the constant LOG2E is: " + LOG2E_value

LOG10E_value = Math.LOG10E
console.log "The value of the constant LOG10E is: " + LOG10E_value

PI_value = Math.PI
console.log "The value of the constant PI is: " + PI_value

SQRT1_2_value = Math.SQRT1_2
console.log "The value of the constant SQRT1_2 is: " + SQRT1_2_value

SQRT2_value = Math.SQRT2
console.log "The value of the constant SQRT2 is: " + SQRT2_value

c:\> coffee -c math_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var LN10_value, LN2_value, LOG10E_value, LOG2E_value, PI_value, SQRT1_2_value, SQRT2_value, e_value;

  e_value = Math.E;

  console.log("The value of the constant E is: " + e_value);

  LN2_value = Math.LN2;

  console.log("The value of the constant LN2 is: " + LN2_value);

  LN10_value = Math.LN10;

  console.log("The value of the constant LN10 is: " + LN10_value);

  LOG2E_value = Math.LOG2E;

  console.log("The value of the constant LOG2E is: " + LOG2E_value);

  LOG10E_value = Math.LOG10E;

  console.log("The value of the constant LOG10E is: " + LOG10E_value);

  PI_value = Math.PI;

  console.log("The value of the constant PI is: " + PI_value);

  SQRT1_2_value = Math.SQRT1_2;

  console.log("The value of the constant SQRT1_2 is: " + SQRT1_2_value);

  SQRT2_value = Math.SQRT2;

  console.log("The value of the constant SQRT2 is: " + SQRT2_value);

}).call(this);

c:\> coffee math_example.coffee

The value of the constant E is: 2.718281828459045
The value of the constant LN2 is: 0.6931471805599453
The value of the constant LN10 is: 2.302585092994046
The value of the constant LOG2E is: 1.4426950408889634
The value of the constant LOG10E is: 0.4342944819032518
The value of the constant PI is: 3.141592653589793
The value of the constant SQRT1_2 is: 0.7071067811865476
The value of the constant SQRT2 is: 1.4142135623730951

try
  x = y+20
  console.log "The value of x is :" +x
catch e
  console.log "exception/error occurred"
  console.log "The STACKTRACE for the exception/error occurred is ::"
  console.log e.stack

c:\> coffee -c Exception_handling.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var e, error, x;

  try {
    x = y + 20;
    console.log("The value of x is :" + x);
  } catch (error) {
    e = error;
    console.log("exception/error occurred");
    console.log("The STACKTRACE for the exception/error occurred is ::");
    console.log(e.stack);
  }

}).call(this);

c:\> coffee Exception_handling.coffee

exception/error occurred
The STACKTRACE for the exception/error occurred is ::
ReferenceError: y is not defined
  at Object.<anonymous> (C:\Examples\strings_exceptions\Exception_handling.coffee:3:7)
  at Object.<anonymous> (C:\Examples\strings_exceptions\Exception_handling.coffee:2:1)
  at Module._compile (module.js:413:34)
  at Object.exports.run (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\coffee-script.js:134:23)
  at compileScript (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\command.js:224:29)
  at compilePath (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\command.js:174:14)
  at Object.exports.run (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\command.js:98:20)
  at Object.<anonymous> (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\bin\coffee:7:41)
  at Module._compile (module.js:413:34)
  at Object.Module._extensions..js (module.js:422:10)
  at Module.load (module.js:357:32)
  at Function.Module._load (module.js:314:12)
  at Function.Module.runMain (module.js:447:10)
  at startup (node.js:139:18)
  at node.js:999:3

try
  x = y+20
  console.log "The value of x is :" +x
catch e
  console.log "exception/error occurred"
  console.log "The STACKTRACE for the exception/error occurred is ::"
  console.log e.stack

finally
  console.log "This is the statement of finally block"

c:\> coffee -c Exception_handling_finally.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var e, error, x;

  try {
    x = y + 20;
    console.log("The value of x is :" + x);
  } catch (error) {
    e = error;
    console.log("exception/error occurred");
    console.log("The STACKTRACE for the exception/error occurred is ::");
    console.log(e.stack);
  } finally {
    console.log("This is the statement of finally block");
  }

}).call(this);

c:\> coffee Exception_handling_finally.coffee

exception/error occurred
The STACKTRACE for the exception/error occurred is ::
ReferenceError: y is not defined
  at Object.<anonymous> (C:\Examples\strings_exceptions\Exception_handling.coffee:3:7)
  at Object.<anonymous> (C:\Examples\strings_exceptions\Exception_handling.coffee:2:1)
  at Module._compile (module.js:413:34)
  at Object.exports.run (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\coffee-script.js:134:23)
  at compileScript (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\command.js:224:29)
  at compilePath (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\command.js:174:14)
  at Object.exports.run (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\lib\coffee-script\command.js:98:20)
  at Object.<anonymous> (C:\Users\Tutorialspoint\AppData\Roaming\npm\node_modules\coffee-script\bin\coffee:7:41)
  at Module._compile (module.js:413:34)
  at Object.Module._extensions..js (module.js:422:10)
  at Module.load (module.js:357:32)
  at Function.Module._load (module.js:314:12)
  at Function.Module.runMain (module.js:447:10)
  at startup (node.js:139:18)
  at node.js:999:3

This is the statement of finally block

myFunc = ->
  a = 100
  b = 0
  try
    if b == 0
      throw ("Divided by zero error.")
    else
      c = a / b
  catch e
    console.log "Error: " + e

myFunc()

c:\> coffee -c throw_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var myFunc;

  myFunc = function() {
    var a, b, c, e, error;
    a = 100;
    b = 0;
    try {
      if (b === 0) {
        throw "Divided by zero error.";
      } else {
        return c = a / b;
      }
    } catch (error) {
      e = error;
      return console.log("Error: " + e);
    }
  };

  myFunc();

}).call(this);

c:\> coffee throw_example.coffee

Divided by zero error.

pattern =/pattern/

input_data ="hello how are you welcome to <b>Tutorials Point.</b>"
regex = /<b>(.*)<\/b>/
result = regex.exec(input_data)
console.log result

c:\> coffee -c regex_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var input_data, regex, result;

  input_data = "hello how are you welcome to <b>Tutorials Point.</b>";

  regex = /<b>(.*)<\/b>/;

  result = regex.exec(input_data);

  console.log(result);

}).call(this);

c:\> coffee regex_example.coffee

[ '<b>Tutorials Point.</b>',
  'Tutorials Point.',
  index: 29,
  input: 'hello how are you welcome to <b> Tutorials Point.</b>' ]

input_data ="hello how are you welcome to Tutorials Point."
heregex = ///
<b>  #bold opening tag
(.*) #the tag value
</b>  #bold closing tag
///
result = heregex.exec(input_data)
console.log result

c:\> coffee -c heregex_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var heregex, input_data, result;

  input_data = "hello how are you welcome to <b> Tutorials Point.</b>";

  heregex = /<b>(.*) <\/b>/;

  result = heregex.exec(input_data);

  console.log(result);

}).call(this);

c:\> coffee heregex_example.coffee

[ '<b>Tutorials Point.</b>',
  'Tutorials Point.',
  index: 29,
  input: 'hello how are you welcome to <b>Tutorials Point.</b>' ]

class Student

var Student;

Student = (function() {
  function Student() {}

  return Student;

})();

#Defining a class
class Student
  constructor: (@name)->

#instantiating a class by passing a string to constructor
student = new Student("Mohammed");
console.log "the name of the student is :"+student.name

c:\>coffee -c constructor_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var Student, student;

  Student = (function() {
    function Student(name) {
      this.name = name;
    }

    return Student;

  })();

  student = new Student("Mohammed");

  console.log("The name of the student is :"+student.name);

}).call(this);

coffee constructor_example.coffee

The name of the student is :Mohammed

#Defining a class
class Student
  name="Ravi"
  age=24
  message: ->
    "Hello "+name+" how are you"

#instantiating a class by passing a string to constructor
student = new Student();
console.log student.message()

// Generated by CoffeeScript 1.10.0
(function() {
  var Student, student;

  Student = (function() {
    var age, name;

    function Student() {}

    name = "Ravi";

    age = 24;

    Student.prototype.message = function() {
      return "Hello " + name + " how are you";
    };

    return Student;

  })();

  student = new Student();

  console.log(student.message());

}).call(this);

#Defining a class
class Student
  @message:(name) ->
    "Hello "+name+" how are you"
console.log Student.message("Raju")

c:\>coffee -c  static_properties_example.coffee

// Generated by CoffeeScript 1.10.0
(function() {
  var Student;

  Student = (function() {
    function Student() {}

    Student.message = function(name) {
      return "Hello " + name + " how are you";
    };

    return Student;

  })();

  console.log(Student.message("Raju"));

}).call(this);

c:\>coffee static_properties_example.coffee

Hello Raju how are you

#Defining a class
class Add
   a=20;b=30

   addition:->
     console.log "Sum of the two numbers is :"+(a+b)

class My_class extends Add

my_class = new My_class()
my_class.addition()

#Defining a class
class Add
   constructor:(@a,@b) ->

   addition:=>
     console.log "Sum of the two numbers is :"+(@a+@b)

class Mul extends Add
   constructor:(@a,@b) ->
     super(@a,@b)

   multiplication:->
     console.log "Product of the two numbers is :"+(@a*@b)

mul = new Mul(10,20)
mul.addition()
mul.multiplication()

<html>

   <head>
      <title>The jQuery Example</title>
      <script type = "text/javascript"
         src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>

      <script type = "text/javascript" language = "javascript">
         $(document).ready(function() {
            $("div").click(function () {
               $(this).before('<div class="div"></div>' );
            });
         });
      </script>

      <style>
         .div{ margin:10px;padding:12px; border:2px solid #666; width:60px;}
      </style>
   </head>

   <body>

      <p>Click on any square below:</p>
      <span id = "result"> </span>

      <div class = "div" style = "background-color:blue;"></div>
      <div class = "div" style = "background-color:green;"></div>
      <div class = "div" style = "background-color:red;"></div>

   </body>

</html>

 <html>

   <head>
      <title>The jQuery Example</title>
      <script type = "text/javascript"
         src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
      <script src="http://coffeescript.org/extras/coffee-script.js"></script>

      <script type="text/coffeescript">
        $(document).ready ->
          $('div').click ->
            $(this).before '<div class="div"></div>'
            return
          return
      </script>

      <style>
         .div{ margin:10px;padding:12px; border:2px solid #666; width:60px;}
      </style>
   </head>

   <body>

      <p>Click on any square below:</p>
      <span id = "result"> </span>

      <div class = "div" style = "background-color:blue;"></div>
      <div class = "div" style = "background-color:green;"></div>
      <div class = "div" style = "background-color:red;"></div>

   </body>

</html>

Tutorials Point is giving self learning content
to teach the world in simple and easy way!!!!!

var fs = require("fs");
var data = fs.readFileSync('input.txt');
console.log(data.toString());
console.log("Program Ended");

$ node main.js

Tutorials Point is giving self learning content
to teach the world in simple and easy way!!!!!
Program Ended

Tutorials Point is giving self learning content
to teach the world in simple and easy way!!!!!

var fs = require("fs");
fs.readFile('input.txt', function (err, data) {
  if (err) return console.error(err);
    console.log(data.toString());
});
console.log("Program Ended");

$ node main.js

Program Ended
Tutorials Point is giving self learning content
to teach the world in simple and easy way!!!!!