Returns the internal numerical codes of the characters
`s[i], s[i+1], ..., s[j]`. The default value for `i` is 1; the default
value for `j` is `i`. These indices are corrected following the same rules
of function `Library.string.sub()`.


string.byte

Returns the internal numerical codes of the characters
`s[i], s[i+1], ..., s[j]`. The default value for `i` is 1; the default
value for `j` is `i`. These indices are corrected following the same rules
of function string.sub.


Receives zero or more integers and returns a string with length equal to
the number of arguments that has each character has the internal numerical
code equal to its corresponding argument.


string.char

Looks for the first match of pattern in the string `s`. If it finds a
match, then it returns the indices of `s` where the occurrence starts and
ends; otherwise, it returns nil. A third, optional numerical argument init
specifies where to start the search; its default value is 1 and can be
negative. A value of true as a fourth, optional argument plain turns off
the pattern matching facilities, so the function does a plain "find
substring" operation, with no characters in the pattern being considered
"magic". Note that if _plain_ is given, then _init_ must be given as well.


string.find

pattern

init

plain

Looks for the first match of pattern in the string `s` and returns the
indices of `s` where the occurrence starts and ends.


Returns a formatted version of its variable number of arguments following
the description given in its first argument, which must be a string.

You can convert variables into user-friendly strings of text using the
`Library.string.format()` function. The function requires the following
format:

`%[flags][width].[precision][specifier]`.

#### Specifiers

The most important part of string formatting is the **specifiers**.

<table>
 <thead>
 <tr>
 <th>Specifier</th>
 <th>Accepts</th>
 <th>Outputs</th>
 <th>Example Output</th>
 </tr>
 </thead>
 <tbody>
 <tr>
 <td>c</td>
 <td>integer</td>
 <td></td>
 <td>3</td>
 </tr>
 <tr>
 <td>d or i</td>
 <td>integer</td>
 <td>Decimal representation.</td>
 <td> 321 </td>
 </tr>
 <tr>
 <td>e or E</td>
 <td>float</td>
 <td>Scientific notation using e or E.</td>
 <td>3.296e2 3.296E2</td>
 </tr>
 <tr>
 <td>f</td>
 <td>float</td>
 <td></td>
 <td>3231.1231</td>
 </tr>
 <tr>
 <td>g or G</td>
 <td>float</td>
 <td>The shorter of e/E and f.</td>
 <td>3E14 3e14</td>
 </tr>
 <tr>
 <td>o</td>
 <td>integer</td>
 <td>Octal representation.</td>
 <td>610</td>
 </tr>
 <tr>
 <td>q</td>
 <td>string</td>
 <td>String in a form suitable to be safely read back by the Lua interpreter. The string is written between double quotes and all double quotes, new lines, embedded zeros, and backslashes are correctly escaped.</td>
 <td>"print(\"Hi\")"</td>
 </tr>
 <tr>
 <td>s</td>
 <td>string</td>
 <td></td>
 <td>Hello world!</td>
 </tr>
 <tr>
 <td>u</td>
 <td>integer</td>
 <td>Decimal representation.</td>
 <td>3131</td>
 </tr>
 <tr>
 <td>x or X</td>
 <td>integer</td>
 <td>Hexadecimal representation.</td>
 <td>7fa 7FA</td>
 </tr>
 <tr>
 <td>%</td>
 <td></td>
 <td>% followed by another % will return the % sign itself.</td>
 <td>%</td>
 </tr>
 </tbody>
</table>

```
local str = "The magic word is %s"
print(string.format(str, "Roblox"))
-- The magic word is Roblox

local str = "The magic word is %q"
print(string.format(str, "Roblox"))
-- The magic word is "Roblox"

local str = "Skip to \na new line and \nanother new line!"
print(string.format(str, "%q"))
--[[ Output:
Skip to
a new line and
another new line!
]]
```

#### Flags

<table>
<thead>
 <tr>
 <th>Flag</th>
 <th>Description</th>
 </tr>
</thead>
<tbody>
 <tr>
 <td>-</td>
 <td>Left-justify the given field width (see Width below). Right justification is the default.</td>
 </tr>
 <tr>
 <td>+</td>
 <td>Forces a "+" sign to precede a number. Has no effect on negative numbers.</td>
 </tr>
 <tr>
 <td>(space)</td>
 <td>One blank space is inserted before a positive number, while negative numbers are unaffected. This is useful for making positive and negative numbers vertically align in a visual stacked list.</td>
 </tr>
 <tr>
 <td>#</td>
 <td>When used with o and x/X, writes a 0 (octal) or 0x/0X (hex) before values other than zero. When used with e/E and f, forces the output to contain a decimal point, even if no digits would follow (by default, no decimal point is written if no digits follow). When used with g or G, the result is the same as with e or E but trailing zeros are not removed.</td>
 </tr>
 <tr>
 <td>0</td>
 <td>Left-pads the number with zeros instead of empty spaces (see Width below).</td>
 </tr>
</tbody>
</table>

```lua
local str = "%-10d"
print(string.format(str, 300) .. "]")
-- 300 ]
-- There are 7 spaces between '300' and ']'

local str = "%+i versus %+i"
print(string.format(str, 300, -300)) -- +300 versus -300

local str = "There is a% i%% chance of rain in Seattle today."
print(string.format(str, 100))
-- There is a 100% chance of rain in Seattle today.
```

#### Width

<table>
 <thead>
 <tr>
 <th>Width</th>
 <th>Description</th>
 </tr>
 </thead>
 <tbody>
 <tr>
 <td>(number)</td>
 <td>Minimum number of characters to return. If the number of characters to be formatted is less than this number, the result is padded with blank spaces.</td>
 </tr>
 </tbody>
</table>

```lua
local str = "%012i"
print("Score: " .. string.format(str, 15000))
-- Output: Score: 000000015000
-- The output has 12 digits total, left-padded with zeros
```

#### Precision

The default precision is 1. If you give a period without a value, the
default is 0.

<table>
 <thead>
 <tr>
 <th>Precision</th>
 <th>Description</th>
 </tr>
 </thead>
 <tbody>
 <tr>
 <td>.(number)</td>
 <td>For integer specifiers (d, i, o, u, x/X), precision specifies the minimum number of digits to be returned. If the value to be formatted is shorter than this number, the result is padded with leading zeros. A precision of 0 means that no character is written for the value 0. For e/E and f specifiers, this is the number of digits to be printed after the decimal point. For g/G specifiers, this is the maximum number of digits (before the e/E, if present). For s, this is the maximum number of characters to be returned. For c and q, this has no effect.</td>
 </tr>
 </tbody>
</table>

```lua
-- Add decimal with precision of 2 for a currency output
local str = "$%.2f"
print(string.format(str, 300)) -- Output: $300.00

-- Return first 6 letters of a string
local str = "%.6s"
print(string.format(str, "Robloxian")) -- Output: Roblox

local str = "Once upon a time, there was a dragon named %s and it had %.8f horns."
print(string.format(str, "Pi", math.pi))
-- Output: Once upon a time, there was a dragon named Pi and it had 3.14159265 horns.
```

string.format

formatstring

Returns a formatted version of its variable number of arguments following
the description given in its first argument, which must be a string.


Returns an iterator function that returns the next captures from pattern
over the string `s` each time it's called.


string.gmatch

Short for global substitution. Returns a copy of `s` in which all (or the
first n, if given) occurrences of the pattern are substituted (replaced)
with the given `replacement`. The second value returned is the total
number of substitutions made.

The `replacement` can be one of several types, each used differently to
determine the actual string:

- string: The pattern is replaced with the string directly
- table: The string that matched the pattern is looked up in the table as
  a key, and the value (string) is what replaces it, if it exists.
- function: Called with the string that matched the pattern, should return
  the string to replace the matched pattern.

An optional final argument can be provided which specifies the maximum
number of substitutions to make (for example, stop after 2 replacements)

#### Various Examples

```lua
-- Simple replacement
string.gsub("I love tacos!", "tacos", "Roblox") --> I love Roblox! 1
-- Using a pattern (hint: %w+ matches whole words)
string.gsub("I like red!", "%w+", "word") --> word word word 3
-- Replacement table
string.gsub("I play Roblox.", "%w+", {I="Je", play="joue à"}) --> Je joue à Roblox. 3
-- Replacement function
string.gsub("I have 2 cats.", "%d+", function (n) return tonumber(n) * 12 end) --> I have 24 cats. 1
-- Replace only twice
string.gsub("aaa", "a", "b", 2) --> "bba", 2
```


string.gsub

The string whose occurrences of the given pattern shall be replaced.


replacement

Determines what should replace the occurrence(s) of the given pattern.


replacements

The maximum number of substitutions to make.


Returns a copy of `s` in which all or the first `n` occurrences of the
pattern are replaced with the given replacement. The second value returned
is the total number of substitutions made.


string.len

Returns a copy of a string with all uppercase letters changed to
lowercase.


string.lower

Looks for the first match of pattern in the string `s`. If a match is
found, it is returned; otherwise, it returns nil. A third, optional
numerical argument, init, specifies where to start the search; its default
value is 1 and can be negative.


string.match

Looks for the first match of pattern in the string `s`. If a match is
found, it is returned; otherwise, it returns nil. A third, optional
numerical argument, init, specifies where to start the search.


Returns a binary string containing the provided arguments. The description
in the first argument, which must be a string, determines the way the
remaining arguments are packed.


string.pack

format

Returns a binary string containing the provided arguments.


Returns the size in bytes of any string packed with a given description.
You can't use `s` and `z` because they have variable lengths.


string.packsize

Returns the size in bytes of any string packed with a given description.


Returns a string that is the concatenation of `n` copies of the string
`s`.


string.rep

Returns a string that is the string `s` reversed.


string.reverse

Splits a string into parts based on the defined separator character(s),
returning a table of ordered results.

If an empty "slice" is located, that part will be returned as an empty
string. For instance `string.split("abc||def", "|")` will return a table
with three strings: `"abc"`, `""`, and `"def"`.

```lua
local values = input:split(",")
print(values[1], values[2], values[3])
```

Also note that whitespace from the original string will be preserved, for
example `string.split("abc _ def", "_")` will honor the whitespace on both
sides of the `_` separator. By default, the separator character is `,` but
you can specify an alternative character or series of characters.

**Corner Cases**

#### Empty String

```lua
"" --> ""
```

#### Empty Slices

```lua
"foo,,bar" --> "foo", "", "bar"
",foo" --> "", "foo"
"foo," --> "foo", ""
"," --> "", ""
",," --> "", "", ""
```

#### Whitespace Preserved

```lua
"   whitespace   " --> "   whitespace   "
"foo , bar" --> "foo ", " bar"
```

#### Invalid UTF-8

```lua
"\xFF" --> "\xFF"
"\xFD,\xFE" --> "\xFD", "\xFE"
```

#### Unicode

```lua
"，" --> U+FF0C FULLWIDTH COMMA
"我很高兴，你呢？" --> "我很高兴", "你呢？"
"•" --> U+2022 BULLET
"hello•world" --> "hello", "world"
```


string.split

separator

The separator character(s) to be used for splitting the string.


Splits a string into parts based on the defined separator character(s),
returning a table of ordered results.


Returns the substring of `s` that starts at `i` and continues until j. `i`
and `j` can be negative. `i` defaults to 1 and `j` defaults to `-1`.


string.sub

Extracts the values packed in the provided binary string based on the
description in the first argument. The description should match the one
originally used to pack the string. The optional third parameter
determines the byte at which the reading starts.


string.unpack

data

readStart

The values packed into the provided binary string, plus the index of
the first unread byte.


Extracts the values packed in the provided binary string.


Returns a copy of a string with all lowercase letters changed to
uppercase.


string.upper

string

Provides generic functions to manipulate strings.


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The following API key permissions are required to call this endpoint. For more
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The following endpoints are available at paths relative to the base URL.

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application, see [App Registration and Review]({oauth2ReferenceDocLink}).

The following objects describe payloads that are accepted or returned. See each individual endpoint for more information on when these objects are used.

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string

Summary

Functions

Functions

byte

Parameters

Returns

char

Parameters

Returns

find

Parameters

Returns

format

Parameters

Returns

gmatch

Parameters

Returns

gsub

Parameters

Returns

len

Parameters

Returns

lower

Parameters

Returns

match

Parameters

Returns

pack

Parameters

Returns

packsize

Parameters

Returns

rep

Parameters

Returns

reverse

Parameters

Returns

split

Parameters

Returns

sub

Parameters

Returns

unpack

Parameters

Returns

upper

Parameters

Returns