# Autoreplacement for phone numbers

There are many ways to write the same phone number.

`81234567890`

, `+71234567890`

, `1234567890`

and `8 (123) 456-78-90`

are only a few obvious formatting examples for Russian numbers. And if you're getting calls from multiple countries, the number of options is very high.
For a human, those options are not so different. All of them will work if you dial them; it's easy to compare them to understand that they are the same number. However, for software, they are completely different numbers. For example, if you have a contact saved in CRM with a number starting with +7, but you enter the number in the search with 8, then the search may not show this contact.- 1.Autoreplacement modifies client and/or user phone numbers that match
**templates**by replacing whole numbers or their parts with**substitutions**. Multiple patterns can be configured simultaneously. - 2.Replacements are executed before requests are sent to CRM, so autoreplacement affects the creation and search of entities, tasks, and users.
- 3.
**All replacements**are executed for each number one by one in turns. It means that the order of replacements is important, as the execution of the first replacement may make the number match or not match the following templates.

We use the language of regular expressions (regexp) to describe the rules of autoreplacement, the same as we did until now in customizations. This is a commonly used way of matching and modifying text.

To create and test regular expressions, we suggest using online tools, such as regex101.com (choose

**Golang**in the left menu and lower choose**Substitution**to test replacements).**Symbols**

`^`

- beginning of a line`$`

- end of a line`.`

- any symbol`\d`

- a digit`\D`

- not a digit`\w`

- a digit or a letter`\W`

- not a digit and not a letter`\s`

- space (including unusual varieties, such as no-line-break spaces)`\S`

- not a space`[ab\s0-5]`

- either:`a`

,`b`

, space or digit between`0`

and`5`

`abc 123`

- literally "abc 123", possibly as a part of bigger text fragment`abc|123`

- either "abc" or "123", possibly as a part of bigger text fragment`^abc 123$`

- "abc 123" as a whole line without additional text before or after`\(`

,`\)`

,`\[`

,`\]`

,`\{`

,`\}`

,`\+`

,`\?`

,`\*`

,`\.`

,`\|`

,`\\`

- literal representation of symbols that have special meaninng when not preceeded by`\`

**Repetitions**

You can specify how many times a symbol or a group can be repeated immediately after it.

`?`

- 0 or 1 time`+`

- 1 or more times`*`

- any number of times`{5}`

- 5 times`{5,10}`

- 5 to 10 times`{,10}`

- 0 to 10 times`{5,}`

- 5 or more times

For example,

`\d{10}`

means "ten digits", `\+?`

means "zero or one plus sign" and `0+`

means "one or more zeroes".**Groups and substitutions**

Symbols can be combined into groups using brackets. This is useful for repeating multiple symbols. For example,

`(10){3}`

means "101010".
Text from groups can be used in substitutions as `$N`

where `N`

is the number of a group.
For example, when using a pattern `8(\d{6})(\d{4})`

, the substitution `$1`

would mean the contents of the group `(\d{6})`

- the first 6 digits after "8". The substitution `$2`

would mean the contents of the group `(\d{4})`

- the following 4 digits.Pattern | Substitution | Description |
---|---|---|

`^\+?7(\d{10})$` | `8$1` | Replaces prefixes `+7` and `7` in the beginning of a number that consists of a prefix followed by 10 digits with `8` , e.g. `+74951234567` → `84951234567` and `74951234567` → `84951234567`
This pattern is enabled by default |

`^\+7` | `8` | Replaces `+7` in the beginning of any number with `8` , e.g. `+712345671234567` → `812345671234567` |

`.*(\d{10})$` | `8$1` | Replaces a number with 10 in the end with `8` and those 10 digits, e.g. `0071234567890` → `81234567890` |

`^(\d{7})$` | `8495$1` | Adds a prefix `8495` to a 7-digit number, e.g. `1234567` → `84951234567` |

`\D` | (empty string) | Removes all symbold except digits, e.g. `+7 (495) 123-45-67` → `74951234567` |

`[\s()-]` | (empty string) | Removes all spaces, brackets and dashes, e.g. `+7 (495) 123-45-67` → `+74951234567` |

`^(.*)(\d{3})(\d{3})(\d{2})(\d{2})$` | `$1 ($2) $3-$4-$5` | Formats a number as `x (xxx) xxx-xx-xx` , e.g. `+74951234567` → `+7 (495) 123-45-67` |

`^0\d{2}(\d+)$` | `8$1` | Replaces a number composed of "zero, two digits, more digits" with `8` and the digits from the end of a number, e.g. `0771234567890123` → `81234567890123` |

`1234567$` | `7654321` | Replaces `1234567` in the end of a number with `7654321` , e.g. `84951234567` → `84957654321` |

`^84951234567$` | `84957654321` | Replaces a literal number `84951234567` with `84957654321` |

Pattern | Substitution | Description |
---|---|---|

`.*(\d{4}$)` | `$1` | Removes everything except the last 4 digits, e.g. `+71234564321` → `4321` |

`^8123456(\d{4})$` | `$1` | Removes a prefix `8123456` , leaving last 4 digits, e.g. `849576543214321` → `4321` |

`.*123456(\d{4})$` | `$1` | Removes everything except the last 4 digits from a number ending with `123456` and 4 more digits, e.g. `+71234564321` → `4321` |

`^1\d{3}$` | `2$1` | Replaces the first digit `1` of a 4-digit number with `2` , e.g. `1234` → `2234` |

`^1234$` | `4321` | Replaces literal number `1234` with `4321` |