What are global variables in javascript?

Global variables are the variables declared outside a function. Global variables have global scope meaning all scripts and functions on the page can access them. The lifetime of a global variable starts with it's declaration and is deleted when the page is closed. Also, If you assign a value to a variable that has not been declared, it will automatically become a global variable, even if it is present inside a function. function GlobalEx() { // The variable greeting is not declared but a value is assigned. // So it will automatically become a global variable greeting = "JavaScript Global variable example"; } GlobalEx(); // Variable greeting is available outside the function alert(greeting);

Hi Mohan , var iAmGlobal = "some val"; //Global variable declaration //Any place in other part of code function doSomething() { //iAmGlobal = "changed value"; alert(iAmGlobal); //I am accessible here too !! }