We can use “if—else “statements to perform an appropriate action based on condition. We can use” if—else” statement to take decision on the basis of specific condition. If statements are executed if and only if condition passed to the if statements are evaluates to true otherwise else statements are executed.

Syntax of if—else statement
If (<Boolean expression>)
{
                Statement1;
                statement2;
}
Following example demonstrate use of if---else statement
Example 1: if without else
function conditionalOperatorDemo() {
            document.write("Following example demonstrate use of if block without else. <br />");
            var res = 45;
            if (res > 0) {
                document.write("Number is positive. Condition evaluates to true. <br />");
            }
}
Output of the following code snippet is as follows

if --- else in Java Script

Example 2: if with else statement
function conditionalOperatorDemo() {
            document.write("Following example demonstrate use of if block with else. <br />");
            var res = -55;
            if (res > 0) {
                document.write("Number is positive. Condition evaluates to true. <br />");
            }
            else {
                document.write("Number is negative. Condition evaluates to false. <br />");
            }
}
Output of the following code snippet is as follows

if --- else in Java Script

Example 3: Nested if--- else statement
function conditionalOperatorDemo() {
document.write("Following example demonstrate use of nested if else block. <br />");
            var age = 45;
            if (age > 0) {
                if (age > 20 && age < 50) {
                    document.write("Your are valid for this post.");
                }
                else {
                    document.write("You are overage for this post.");
                }
            }
            else {
                document.write("Invalid age you have entered.");
            }
}
Output of the following code snippet is as follows

if --- else in Java Script


  Modified On Nov-29-2017 08:46:13 PM

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