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There are two types of variables in JavaScript.  Global variables have global access and are declared outside of any function. Local variables are those declared inside of function. Lexical Scoping(Nested JavaScript Function) means that in a nested group of functions, the inner functions have access to the variables and other resources of their parent scope. Global variable:- Global variable declares & initialize outside the function, & accessible in from anywhere in the code. The global variable always stored in memory even function execution finish, it always keeps in memory or always accessible from anywhere in the code. Example 1 var message= "hello i am global variable" ; //global variable function a (){ console.log(message); // output: hello i am global variable } function b (){ console.log(message); // output: hello i am global variable } function a() function b() In above example message is a global variable, it can be acces

JavaScript type hoisting with variable function Expression Hoisting is JavaScript default behavior to moving declaration on the top. Variable can be used before its declaration. To understand this, first we need to understand of hoist meaning, hoist means “raise(something) by means of ropes & pulleys”. now we can relate hoisting with JavaScript. JavaScript interpreter moves all declaration on the top at runtime. It is best practice to declare all variable at the top of their respective scopes. , JavaScript is loosely syntax language so it will not throw any error at runtime if the variable used before its declaration. But JavaScript does not allow variable used before its declaration in “use strict” mode. Example 1 In this example, we can see in a normal scenario, when y has declared & then used. in this case, it will give output 10 as excepted. <p id= "demo" ></p> <script> var y; //Declare y y = 10 ;