JavaScript Conditional Statements

1.The if Statement:-

Use the if statement to specify a block of JavaScript code to be executed if a condition is true.

Syntax:-

if (condition) {
//  block of code to be executed if the condition is true
}

Example:-

<!DOCTYPE html>
<html>
<body><p>Display “Good day!” if the hour is less than 18:00:</p>

<p id=”demo”>Good Evening!</p>

<script>
if (new Date().getHours() < 18) {
document.getElementById(“demo”).innerHTML = “Good day!”;
}
</script>

</body>
</html>

Result:-Display “Good day!” if the hour is less than 18:00:

Good day!

2.The  else  statement:-

Use the else statement to specify a block of code to be executed if the condition is false.

Syntax:-

if (condition) {
//  block of code to be executed if the condition is true
} else {
//  block of code to be executed if the condition is false
}

Example:-

<!DOCTYPE html>
<html>
<body><p>Click the button to display a time-based greeting:</p>

<button onclick=”myFunction()”>Try it</button>

<p id=”demo”></p>

<script>
function myFunction() {
var hour = new Date().getHours();
var greeting;
if (hour < 18) {
greeting = “Good day”;
} else {
greeting = “Good evening”;
}
document.getElementById(“demo”).innerHTML = greeting;
}
</script>

</body>
</html>

Result:-Click the button to display a time-based greeting:

Good day