---
description: >-
  This section describes how to use Kotlin extension methods for validation
  checks.
---

# Extension Methods

### **Overview**

**EasyValidation** utilizes the power of Kotlin Extension methods and provides you huge number of [built-in validation rules](https://wajahatkarim.gitbook.io/easyvalidation/usage/built-in-rules) in form of extensions on  `String`, `EditText`, `TextView`, `AutoCompleteTextView`, `TextInputLayout`, and `Spinner` classes.

For example, you can check some validation checks on `EditText` like this:

```kotlin
var txtEmail = findViewById<EditText>(R.id.txtEmail)

// Valid email check
txtName.validEmail() { msg ->
    // Invalid email
    txtName.error = msg
}

// Minimum length check
txtName.minLength(5) {
    txtName.error = it
}
```

### List of Extension Methods

Here is the list of all extension methods for  `String`, `EditText`, `TextView`, `AutoCompleteTextView`, `TextInputLayout`, and `Spinner` classes.

| Method                          | Description                                                                                                                                                                 |
| ------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `validator()`                   | Returns the `Validator` object with text                                                                                                                                    |
| `nonEmpty()`                    | Returns `true` if the text is not empty. And returns `false` if text is empty.                                                                                              |
| `minLength()`                   | Returns `false` if the length of text is less than given minimum length.                                                                                                    |
| `maxLength()`                   | Returns `false` if text length is greater than given length                                                                                                                 |
| `validEmail()`                  | Returns `true` if text is a valid email address.                                                                                                                            |
| `validNumber()`                 | Returns `true` if the text is any valid number                                                                                                                              |
| `greaterThan()`                 | Returns `false` if the text is number less than the given target number                                                                                                     |
| `greaterThanOrEqual()`          | Returns `false` if the text is number less than or equal to the given target number                                                                                         |
| `lessThan()`                    | Returns `false` if the text is number greater than the given target number                                                                                                  |
| `lessThanOrEqaul()`             | Returns `false` if the text is number greater than or equal to the given target number                                                                                      |
| `numberEqualTo()`               | Returns `false` if the text is a valid number and equal to the given target number                                                                                          |
| `allUperCase()`                 | Returns `false` if at least one or more characters are lower case                                                                                                           |
| `allLowerCase()`                | Returns `false` if at least one or more characters are upper case                                                                                                           |
| `atleastOneUperCase()`          | Returns `true` if at least one or more characters are upper case                                                                                                            |
| `atleastOneLowerCase()`         | Returns `true` if at least one or more characters are lower case                                                                                                            |
| `atleastOneNumber()`            | Returns `true` if at least one or more characters are numbers                                                                                                               |
| `startWithNumber()`             | Returns `true` if text starts with any number                                                                                                                               |
| `startWithNonNumber()`          | Returns `false` if text starts with any number                                                                                                                              |
| `noNumbers()`                   | Returns `false` if the text any number or digit.                                                                                                                            |
| `onlyNumbers()`                 | Returns `false` if text contains any alphabetic character                                                                                                                   |
| `noSpecialCharacters()`         | Returns `true` if text contain no special characters                                                                                                                        |
| `atleastOneSpecialCharacters()` | Returns `true` if text contain at least one special characters                                                                                                              |
| `textEqaulTo()`                 | Returns `false` if the text is not equal to the given text                                                                                                                  |
| `textNotEqualTo()`              | Returns `true` if the text is not equal to the given text                                                                                                                   |
| `startsWith()`                  | Returns `true` if the text starts with the given text                                                                                                                       |
| `endsWith()`                    | Returns `true` if the text ends with the given text                                                                                                                         |
| `contains()`                    | Returns `true` if the text contains the given text                                                                                                                          |
| `notContains()`                 | Returns `false` if the text contains the given text                                                                                                                         |
| `creditCardNumber()`            | Returns `true` if the text is valid credit card number. This supports Visa, Master Card, American Express, Diners Club, Discover, and JCB.                                  |
| `creditCardNumberWithSpaces()`  | Returns `true` if the text is valid credit card number with spaces between 4 characters. This supports Visa, Master Card, American Express, Diners Club, Discover and JCB.  |
| `creditCardNumberWithDashes()`  | Returns `true` if the text is valid credit card number with dashes between 4 characters. This supports Visa, Master Card, American Express, Diners Club, Discover, and JCB. |
| `validUrl()`                    | Returns `true` if the text is a valid URL                                                                                                                                   |
| `regex()`                       | Returns `true` if the text matches passed `RegEx` pattern.                                                                                                                  |

