javascript class methods code example

Example 1: javascript create class

class Person {
 constructor(name, age) {
   this.name = name;
   this.age = age;
 }
  present = () => { //or present(){
  	console.log(`Hi! i'm ${this.name} and i'm ${this.age} years old`) 
  }
}
let me = new Person("tsuy", 15);
me.present();
// -> Hi! i'm tsuy and i'm 15 years old.

Example 2: javascript class

// Improved formatting of Spotted Tailed Quoll's answer
class Person {
	constructor(name, age) {
		this.name = name;
		this.age = age;
	}
	introduction() {
		return `My name is ${name} and I am ${age} years old!`;
	}
}

let john = new Person("John Smith", 18);
console.log(john.introduction());

Example 3: javascript classes

//use classes by initiating one like so:
class MyClass {
	constructor(FirstProperty, SecondProperty, etcetera) {
    	//The constructor function is called with the new class 
      	//instance's parameters, so this will be called like so:
      	//var classExample = new MyClass("FirstProperty's Value", ...)
      this.firstProperty = FirstProperty;
      this.secondProperty = SecondProperty;
    }
  //creat methods just like functions:
  method(Parameters) {
  	//Code Here
  }
  //getters are properties that are calculated when called, versus fixed
  //variables, but still have no parenthesis when used
  get getBothValues() 
  {
  	return [firstProperty, secondProperty];
  }
}
//Note: this is all syntax sugar reducing the boilerplate versus a
// function-defined object.

Example 4: javascript class

class Rectangle {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
  // Getter
  get area() {
    return this.calcArea();
  }
  // Method
  calcArea() {
    return this.height * this.width;
  }
}

const square = new Rectangle(10, 10);

console.log(square.area); // 100

Example 5: get methods of class javascript

class Hi {
	constructor() {
      console.log("hi");
    }
   	my_method(){}
  	static my_static_method() {}
}

function getMethods(cl) {
  return Object.getOwnPropertyNames(cl.prototype)
}

console.log(getMethods(Hi)) // => [ 'constructor', 'my_method' ]

Example 6: class methods parameters python

class Foo          (object):
    # ^class name  #^ inherits from object

    bar = "Bar" #Class attribute.

    def __init__(self):
        #        #^ The first variable is the class instance in methods.  
        #        #  This is called "self" by convention, but could be any name you want.
        #^ double underscore (dunder) methods are usually special.  This one 
        #  gets called immediately after a new instance is created.

        self.variable = "Foo" #instance attribute.
        print self.variable, self.bar  #<---self.bar references class attribute
        self.bar = " Bar is now Baz"   #<---self.bar is now an instance attribute
        print self.variable, self.bar  

    def method(self, arg1, arg2):
        #This method has arguments.  You would call it like this:  instance.method(1, 2)
        print "in method (args):", arg1, arg2
        print "in method (attributes):", self.variable, self.bar


a = Foo() # this calls __init__ (indirectly), output:
                 # Foo bar
                 # Foo  Bar is now Baz
print a.variable # Foo
a.variable = "bar"
a.method(1, 2) # output:
               # in method (args): 1 2
               # in method (attributes): bar  Bar is now Baz
Foo.method(a, 1, 2) #<--- Same as a.method(1, 2).  This makes it a little more explicit what the argument "self" actually is.

class Bar(object):
    def __init__(self, arg):
        self.arg = arg
        self.Foo = Foo()

b = Bar(a)
b.arg.variable = "something"
print a.variable # something
print b.Foo.variable # Foo