# Boolean in JavaScript

## What are Booleans?

1. Data Type: Booleans are a basic data type in JavaScript.
    
2. Two values: Values can be only true or false.
    
3. 'true' is a string, not a boolean.
    
4. for eg.
    

`console.log(5<9);`

The output would be true because we know that 5 is less than 9 so it returns true as a output.

now if we use `typeof()` operator, it will give the type of our expression which is boolean.

**Note**: If you wrap `true` or `false` in a quote, then they are considered as a string.

For example,

```javascript
const a = 'true';
console.log(typeof a); // string
```

## JavaScript Boolean Methods

Here is a list of built-in boolean methods in JavaScript.

| Method | Description |
| --- | --- |
| `toString()` | returns a boolean value by converting boolean to a string |
| `valueOf()` | returns the primitive value of a boolean |

**Example: Using toString()**

```javascript
let count = false;

// converting to string
let result = count.toString();

console.log(result);
console.log(typeof result);
```

**Output**

```javascript
false
string
```

**Example: Using valueOf()**

```javascript
let count = true;

// converting to string
let result = count.valueOf();

console.log(result);

console.log(typeof result);
```

**Output**

```javascript
true
boolean
```

In JavaScript, `undefined`, `null`, **0**, `NaN`, `''` converts to `false`. For example,

```javascript
let result;
// empty string
result = Boolean('');
console.log(result); // false

result = Boolean(0);
console.log(result); // false

result = Boolean(undefined);
console.log(result); // false

result = Boolean(null);
console.log(result); // false

result = Boolean(NaN);
console.log(result); // false
```