The Shadowy World of Variables.
Variable
In computer programming, a variable or scalar is a storage location paired with an associated symbolic name (an identifier), which contains some known or unknown quantity or information referred to as a value.Variables are placeholders for an value.
For example:
int a=100; //
say a represents placeholder of 100 value.
Shadowing of Variables
Whenever we are using same variable name for holding differnet data in different blocks, then that support of programming knowldge id called as Shadow of variables.
int a=10;
{
int a=100;
{
int a=1000;
}
}
{
int a=100;
{
int a=1000;
}
}
http://facebook.com/sushantmane7ftp://10.10.7.14/
URL
URL(Uniform Resource Locator) locates as well as identifies a resource.
URL defines the network location of a specific resource and states
how that resource can be obtained.
For example:
http://sushantmane.github.io/ is a URL with location
sushantmane.github.io of resource and http is a protocol to access
that resource.
ftp://10.10.7.14/ug2011/n2/sushant.pdf is a URL with location
10.10.7.14/ug2011/n2/sushant.pdf of resource and ftp is a protocol to access
that resource.
Note: All URLs are URIs. But all URIs are not URLs.
URN
URI(Uniform Resource Name), a type of URI, basically states what something is, but do not have information on how to access it.For example:
author: James F. Kurose
title: Computer Networking: A Top-Down Approach
ISBN-10: 8131790541
this is URN and is pointed by URL to
Computer Networking: A Top-Down Approach