JavaScript Conditional Statements

JavaScript Conditional statements are used to control some actions based on various conditions. For different decisions, we want to perform different actions. The JavaScript conditional statements can be used in code for this purpose. If the condition is true it performed an action or if the condition is false it performed another action.

cond
Working of JavaScript Conditional Statements

JavaScript Conditional Statements – Types

Following conditional statements are available in JavaScript.

JavaScript Conditional Statements
  • If statement
  • Else statement
  • Else if statement
  • Switch statement (You will learn about switch staement in next chapter)

The if Statement

If statement is used to specify a block of JavaScript code to be executed if the condition comes true. Its syntax is given below:

Remember that if the statement is in lower case, writing the uppercase letters (If or IF) will generate an error.

<!DOCTYPE html>
<html>
<body>

<script>
var m = 85;
if (m > 70) {
  document.write("You are passed!");
}
</script>

</body>
</html>

Output:

image 99

The else Statement

Else statement is used to specify a block of code to be executed if the condition comes false. Its syntax is given below:

Consider the below example to understand this concept:

<!DOCTYPE html>
<html>
<body>

<script>
var m = 32;
if (m > 33) {
  document.write("You are passed!");
} else {
  document.write("You are failed!");
}
</script>

</body>
</html>

Output:

image 100

The else if Statement

The else if statement is used to specify a new condition if the first condition comes false. Its syntax is given below:

Consider the below example to understand this concept: 

<!DOCTYPE html>
<html>
<body>

<script>
var m = 55;
if (m > 80) {
  document.write("Excellent!");
} else if (m > 50) {
  document.write("Average!");
} else {
  document.write("Below Average!");
}
</script>

</body>
</html>

Output:

image 101