Conditional Examples(if - else- switch case) in JavaScript

In this article you will learn the basics of JavaScript conditions and create your conditional examples in JavaScript .

Conditional Examples(if - else- switch case) in JavaScript

Conditional Examples(if - else- switch case) in JavaScript

     

In this article you will learn the basics of JavaScript conditions and create your conditional examples in JavaScript .

About Conditional Statement
First of all we write the code after that we want to perform the different actions for different decisions. We can use conditional statements in our code. Conditional statements in JavaScript are used to perform different actions based on different conditions.

There are following types of Conditional Statements:-

  • if statement:- It means the condition is true then our writing code is executed other wise our code is not execute . 
     Syntax for the if statement:-
       if ( expression )
       {
        statement1
        statement2
        }
  • if - else statement:- This statement is used to when the condition is true then our code to execute and when the condition is false then our written code is not execute.
    Syntax for the if - else statement:-
       if (expression)
        statement1
        else if (expression2)
        statement2
        else
        statement3
  • if...else if....else statement -This statement is used to if you want to select one of many blocks of code to be executed .
  • switch statement:-This statement is used to if you want to select one of many blocks of code to be executed.
    Syntax for the switch statement:-
       switch (expression)
       {
       case1: 
       statement1
       break
       case2: 
       statement2
       break
       default: 
       statement3;
        }

 This example is if - else statement. It display the first of all the sum of two numbers and check the condition after that it execute the code.

<html>
<head>
<script language="javascript">
function showAlert()
{
var a=20;
var b=10;
var sum=0;
sum=a+b;
document.write(" sum= "+sum);
if(sum==3)
{
document.write("Condition is true");
document.write("This is my first if statement program");
}
false
{
document.write("Condition is false");
document.write(" This is my first if -else statement program");
}
}
</script>
</head>
<body>

<script language="javascript">

showAlert();

</script>

</body>
</html>

 

This example is display to all months in a year for using the switch case:-

<body> 
<script type="text/javascript"> 
var n=0;
n=
prompt("Enter a number between 1 to 12:") 
switch(n) 
{
case(n="1"): 
document.write("January");
break
case(n="2"): 
document.write("Febuary");
break
case(n="3"): 
document.write("March");
break
case(n="4"):
document.write("April");
break
case(n="5"):
document.write("May");
break
case(n="6"):
document.write("June");
break
case(n="7"):
document.write("July");
break
case(n="8"):
document.write("August");
break
case(n="9"):
document.write("September");
break
case(n="10"):
document.write("October");
break
case(n="11"):
document.write("November");
break
default:
document.write("December"); 
break
}
</script> 
</body>