Java Script Functions

Java Script has some important build in functions like

alert()

alert("Hello There, this is an Alert Message!!!");

confirm()

confirm("Hello There, are you sure you want to do this ? ");

​Return

• if the cancel button is pressed, the return value will be false
• if the ok button is pressed, the return value will be true

prompt()

var userName = prompt("What is your name?");

confirm("are you sure about your name : " + userName + " ? ");

Return 

• if the cancel button is pressed, the return value will be null (an object)
• if there ok button is pressed and there is a string in the text field, the return value will be a string 

typeof operator

Return the type of the value within the expression

Sample

typeof true ;                        // boolean
typeof "This is a string" ;          // string
typeof 42 ;                          // number
typeof undefined ;                   // undefined
typeof null ;                        // object