# lessThan()

## `Inequality.prototype.lessThan()`

Checks whether the [primitive value](https://developer.mozilla.org/en-US/docs/Glossary/Primitive#primitive_wrapper_objects_in_javascript) of a child class instance is **less** than the given [`value`](#value-number).

{% code title="inequality.class.ts" %}

```typescript
public lessThan(value: number): boolean {
  return this.#less.than(value);
}
```

{% endcode %}

### Parameters

#### `value:`[<mark style="color:green;">`number`</mark>](https://www.typescriptlang.org/docs/handbook/basic-types.html#number)

A [rest parameter](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters) of the numbers to test.

### Return type

#### [<mark style="color:green;">`boolean`</mark>](https://www.typescriptlang.org/docs/handbook/basic-types.html#boolean)

### Returns

The **return value** is a [`boolean`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) indicating whether the [primitive value](https://developer.mozilla.org/en-US/docs/Glossary/Primitive#primitive_wrapper_objects_in_javascript) of a child class instance is **less** than the given [`value`](#value-number).

## Example usage

```typescript
// Example usage.
import { Inequality } from '@angular-package/range';

// Define the `Year` class and extend it with `Inequality`.
class Year<Value extends number> extends Inequality<Value> {}

// Initialize `Year`.
const year = new Year(1981);

// Returns Year {1981} of Year<1981>.
year;

// Returns `true`. 1981 < 1982.
year.lessThan(1982);

// Returns `false`. 1981 < 1980.
year.lessThan(1980);
```