Boolean Values
Very often, in programming, you will need a data type that can only have one of two values, like
- YES / NO
- ON / OFF
- TRUE / FALSE
For this, JavaScript has a Boolean data type. It can only take the values true or false.
The Boolean() Function
You can use the Boolean() function to find out if an expression (or a variable) is true:
JavaScript Booleans
Display the value of Boolean(10 > 9):
true
Example
<!DOCTYPE html>
<html>
<body>
<h1>JavaScript Booleans</h1>
<p>Display the value of Boolean(10 > 9):</p>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML = Boolean(10 > 9);
</script>
</body>
</html>
Comparisons and Conditions
The chapter JS Comparisons gives a full overview of comparison operators.
The chapter JS Conditions gives a full overview of conditional statements.
Here are some examples:
| Operator | Description | Example |
|---|---|---|
| == | equal to | if (day == "Monday") |
| > | greater than | if (salary > 9000) |
| < | less than | if (age < 18) |
No comments:
Post a Comment