Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
When you can use a JavaScript variable before it is declared, it is done using a technique called hoisting. The parser read through the complete function before running it.The behavior in which a variable appears to be used before it is declared is known as hoisting −For example, the following,points =200; var points;The above works the same like the following −var points; ponts = 200;
The “double tilde” (~~) operator is a double NOT Bitwise operator. Use it as a substitute for Math.floor(), since it’s faster.ExampleYou can try to run the following code to learn about double tilde operator − var a = 2; var b,c, d; b = ~~a; c = Math.floor(a); d = ~~b=== c; document.write(b); document.write(""+c); document.write(""+d); // They are equal
The HTML DOM input month step property returns and modify the value of the step attribute of input month field in an HTML document.SyntaxFollowing is the syntax −1. Returning stepobject.step2. Modifying stepobject.step = “number”ExampleLet us see an example of HTML DOM input month step property − Live Demo html{ height:100%; } body{ text-align:center; color:#fff; background: linear-gradient(62deg, #FBAB7E 0%, #F7CE68 100%) center/cover no-repeat; height:100%; } p{ font-weight:700; font-size:1.1rem; } input{ ... Read More
The HTML DOM input month max property returns and modify the value of the max attribute of the input field of type=”month” in a HTML document.SyntaxFollowing is the syntax −1. Returning maxobject.max2. Modifying maxobject.max = “YYYY-MM”Here, YYYY represent year and MM represent month like “2019-02”ExampleLet us see an example of HTML DOM input month max property − Live Demo html{ height:100%; } body{ text-align:center; color:#fff; background: linear-gradient(62deg, #FBAB7E 0%, #F7CE68 100%) center/cover no-repeat; height:100%; } ... Read More
The hasattr() method in PythonThe hasattr() method returns true if an object has the given named attribute and false if it does not.SyntaxThe syntax of hasattr() method is −hasattr(object, name)The hasattr() is called by getattr() to check to see if AttributeError is to be raised or not.The hasattr() method takes two parameters −The hasattr() method returns −True, if object has the given named attributeFalse, if object has no given named attributeExampleclass Male: age = 21 name = 'x' x = Male() print('Male has age?:', hasattr(x, 'age')) print('Male has salary?:', hasattr(x, 'salary'))OutputThis gives the output('Male has age?:', ... Read More
Python getattr()The getattr() method returns the value of the named attribute of an object. If not found, it returns the default value provided to the function.SyntaxThe syntax of getattr() method is −getattr(object, name[, default])The getattr() method can take multiple parameters −The getattr() method returns −value of the named attribute of the given objectdefault, if no named attribute is foundAttributeError exception, if named attribute is not found and default is not definedExampleclass Male: age = 21 name = "Abel" x = Male() print('The age is:', getattr(x, "age")) print('The age is:', x.age)OutputThis gives the output('The age is:', 21) ... Read More
Class variables vs Instance VariablesAll variables outside the class __init__ function in Python are class variables while those inside the same are instance variables. The difference between the class variables and instance variables is understood better by examining the code belowExampleclass MyClass: stat_elem = 456 def __init__(self): self.object_elem = 789 c1 = MyClass() c2 = MyClass() # Initial values of both elements >>> print c1.stat_elem, c1.object_elem 456 789 >>> print c2.stat_elem, c2.object_elem 456 789 # Let's try changing the static element MyClass.static_elem = 888 >>> print c1.stat_elem, c1.object_elem 888 789 >>> print ... Read More
On re-declaring a variable in JavaScript, the variable value still remains the same.ExampleLet’s see an example. Here, we are declaring the variable age −
The following is stated about declaration and initialization of a variable in ECMAScript specification −A var statement declares variables that are scoped to the running execution context’s VariableEnvironment. Var variables are created when their containing Lexical Environment is instantiated and are initialized to undefined when created. [...] A variable defined by a VariableDeclaration with an Initializer is assigned the value of its Initializer’s AssignmentExpression when the VariableDeclaration is executed, not when the variable is created.The above defines the difference:All variables are initialized with the value undefined.Variables declarations are initialized with undefined upon the initialization of their lexical environment.This initialization does ... Read More
selfThe word 'self' is used to represent the instance of a class. By using the "self" keyword we access the attributes and methods of the class in python.__init__ method"__init__" is a reseved method in python classes. It is called as a constructor in object oriented terminology. This method is called when an object is created from a class and it allows the class to initialize the attributes of the class.ExampleFind out the cost of a rectangular field with breadth(b=120), length(l=160). It costs x (2000) rupees per 1 square unitclass Rectangle: def __init__(self, length, breadth, unit_cost=0): self.length ... Read More