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Functions for Replacing in Strings

General strings functions and functions for searching in strings are described separately.

overlay​

Replace part of the string input with another string replace, starting at the 1-based index offset.

Syntax

Parameters

  • s: A string type String.
  • replace: A string type String.
  • offset: An integer type Int (1-based). If offset is negative, it is counted from the end of the string s.
  • length: Optional. An integer type Int. length specifies the length of the snippet within the input string s to be replaced. If length is not specified, the number of bytes removed from s equals the length of replace; otherwise length bytes are removed.

Returned value

Example

Result:

Result:

overlayUTF8​

Replace part of the string input with another string replace, starting at the 1-based index offset.

Assumes that the string contains valid UTF-8 encoded text. If this assumption is violated, no exception is thrown and the result is undefined.

Syntax

Parameters

  • s: A string type String.
  • replace: A string type String.
  • offset: An integer type Int (1-based). If offset is negative, it is counted from the end of the input string s.
  • length: Optional. An integer type Int. length specifies the length of the snippet within the input string s to be replaced. If length is not specified, the number of characters removed from s equals the length of replace; otherwise length characters are removed.

Returned value

Example

Result:

replaceOne​

Replaces the first occurrence of the substring pattern in haystack by the replacement string.

Syntax

replaceAll​

Replaces all occurrences of the substring pattern in haystack by the replacement string.

Syntax

Alias: replace.

replaceRegexpOne​

Replaces the first occurrence of the substring matching the regular expression pattern (in re2 syntax) in haystack by the replacement string.

replacement can contain substitutions \0-\9. Substitutions \1-\9 correspond to the 1st to 9th capturing group (submatch), substitution \0 corresponds to the entire match.

To use a verbatim \ character in the pattern or replacement strings, escape it using \. Also keep in mind that string literals require extra escaping.

Syntax

Example

Converting ISO dates to American format:

Result:

Copying a string ten times:

Result:

replaceRegexpAll​

Like replaceRegexpOne but replaces all occurrences of the pattern.

Alias: REGEXP_REPLACE.

Example

Result:

As an exception, if a regular expression worked on an empty substring, the replacement is not made more than once, e.g.:

Result:

regexpQuoteMeta​

Adds a backslash before these characters with special meaning in regular expressions: \0, \\, |, (, ), ^, $, ., [, ], ?, *, +, {, :, -.

This implementation slightly differs from re2::RE2::QuoteMeta. It escapes zero byte as \0 instead of \x00 and it escapes only required characters. For more information, see RE2

Syntax

format​

Format the pattern string with the values (strings, integers, etc.) listed in the arguments, similar to formatting in Python. The pattern string can contain replacement fields surrounded by curly braces {}. Anything not contained in braces is considered literal text and copied verbatim into the output. Literal brace character can be escaped by two braces: {{ '{{' }} and {{ '}}' }}. Field names can be numbers (starting from zero) or empty (then they are implicitly given monotonically increasing numbers).

Syntax

Example

With implicit numbers:

translate​

Replaces characters in the string s using a one-to-one character mapping defined by from and to strings. from and to must be constant ASCII strings. If from and to have equal sizes, each occurrence of the 1st character of first in s is replaced by the 1st character of to, the 2nd character of first in s is replaced by the 2nd character of to, etc. If from contains more characters than to, all occurrences of the characters at the end of from that have no corresponding character in to are deleted from s. Non-ASCII characters in s are not modified by the function.

Syntax

Example

Result:

from and to arguments have different lengths:

Result:

translateUTF8​

Like translate but assumes s, from and to are UTF-8 encoded strings.

Syntax

Parameters

Returned value

Examples

Query:

printf​

The printf function formats the given string with the values (strings, integers, floating-points etc.) listed in the arguments, similar to printf function in C++. The format string can contain format specifiers starting with % character. Anything not contained in % and the following format specifier is considered literal text and copied verbatim into the output. Literal % character can be escaped by %%.

Syntax

Example

Query: