# 字符串函数

本节介绍用于处理和操作字符串的函数。在以下函数中，参数为表达式，其中的 s 应被解释为字符串。

所有函数均可在加载脚本和图表表达式中使用，但 Evaluate 只能在加载脚本中使用。

使用每个函数的下拉列表可查看每个函数的简短描述和语法。单击语法描述中的函数名称可了解更多信息。

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### ApplyCodepage

应用不同的代码页到表达式内所述的字段或文本。代码页必须是数字格式。

ApplyCodepage(text, codepage)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Capitalize

Capitalize() 用于返回包含首字母大写的所有单词的字符串。

[**Capitalize**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Capitalize.htm)(text)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Chr

Chr() 用于返回与输入整数对应的 Unicode 字符。

[**Chr**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Chr.htm)(int )

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Evaluate

Evaluate() 用于确定是否可将输入文本字符串作为有效的 QlikView 表达式来计算值，如果可以，则以字符串形式返回该表达式的值。如果输入字符串不是有效的表达式，则返回 NULL。

[**Evaluate**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Evaluate.htm)(expression\_text)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### FindOneOf

FindOneOf() 用于搜索字符串，以便从一组提供的字符中找到任意字符出现的位置。如果不提供第三个参数（值大于 1），则返回任意字符在搜索集合中首次出现的位置。如果未找到匹配值，则返回 0。

[**FindOneOf**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/FindOneOf.htm)(text, char\_set[, count])

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Hash128

Hash128() 用于返回 128 位哈希的组合输入表达式值。结果为 22 个字符的字符串。

[**Hash128**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Hash128.htm)(expr{, expression})

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Hash160

Hash160() 用于返回 160 位哈希的组合输入表达式值。结果为 27 个字符的字符串。

[**Hash160**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Hash160.htm)(expr{, expression})

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Hash256

Hash256() 用于返回 256 位哈希的组合输入表达式值。结果为 43 个字符的字符串。

[**Hash256**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Hash256.htm)(expr{, expression})

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Index

Index() 用于搜索字符串，以便找到所提供子字符串第 n 次出现的开始位置。可选的第三个参数用于提供值 n，如果省略，则值为 1。如果为负值，则从字符串的结尾开始搜索。字符串中的位置从 1 开始编号。

[**Index**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Index.htm) (text, substring[, count])

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### KeepChar

KeepChar() 用于返回包含第一个字符串“text”，但不包含第二个字符串“keep\_chars”所包含的任何字符的字符串。

[**KeepChar**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/KeepChar.htm)(text, keep\_chars)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Left

Left() 用于返回包含输入字符串的第一个（最左端）字符的字符串，其中返回字符串的字符数量由第二个参数确定。

[**Left**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Left.htm)(text, count )

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Len

Len() 用于返回输入字符串的长度。

[**Len**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Len.htm)(text )

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Lower

Lower() 用于将输入字符串中的所有字符转换为小写字符。

[**Lower**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Lower.htm)(text)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### LTrim

LTrim() 用于返回由任何前导空格剪裁的输入字符串。

[**LTrim**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/LTrim.htm)(text)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Mid

Mid() 返回从第二个参数“start”定义的字符位置开始的输入字符串的一部分，并返回第三个参数“count”定义的字符数量。如果省略“count”，则返回输入字符串的剩余部分。输入字符串的第一个字符的编号为 1。

[**Mid**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Mid.htm)(text, start[, count])

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Ord

Ord() 用于返回输入字符串第一个字符的 Unicode 代码点数。

[**Ord**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Ord.htm)(char )

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### PurgeChar

PurgeChar() 返回包含输入字符串（“text”）中的字符，但不包括第二个参数（“remove\_chars”）中的字符的字符串。

[**PurgeChar**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/PurgeChar.htm)(text, remove\_chars)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Repeat

Repeat() 用于构成特定字符串，其中包含重复的输入字符串，重复次数由第二个参数定义。

[**Repeat**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Repeat.htm)(text[, repeat\_count])

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Replace

Replace() 用于使用另一个子字符串替换输入字符串内出现的所有给定子字符串后，返回一个字符串。该函数为非递归函数，从左至右工作。

[**Replace**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Replace.htm)(text, from\_str, to\_str)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Right

Right() 用于返回特定字符串，其中包含输入字符串末尾（最右边）的字符，其中字符数量由第二个参数决定。

[**Right**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Right.htm)(text, count )

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### RTrim

RTrim() 用于返回由任何尾部空格剪裁的输入字符串。

[**RTrim**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/RTrim.htm)(text)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### SubField

Subfield() 用于从父字符串字段提取子字符串组成部分，其中原始记录字段由两个或更多用分隔符分隔的部分构成。

[**SubField**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/SubField.htm)(text, delimiter[, field\_no ])

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### SubStringCount

SubstringCount() 用于返回指定子字符串在输入字符串文本中出现的次数。如果不匹配，则返回 0。

[**SubStringCount**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/SubStringCount.htm)( text , substring)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### TextBetween

TextBetween() 用于返回输入字符串中作为分隔符出现在指定字符之间的文本。

[**TextBetween**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/TextBetween.htm)(text, sub\_string)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Trim

Trim() 用于返回由任何前导和尾部空格剪裁的输入字符串。

[**Trim**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Trim.htm)(text)

[](https://help.qlik.com/en-US/qlikview/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/string-functions.htm)

#### Upper

Upper() 用于将输入字符串中表达式所定义的所有文本字符转换为大写。忽略数字和符号。

[**Upper**](https://help.qlik.com/zh-CN/qlikview/September2025/Subsystems/Client/Content/QV_QlikView/Scripting/StringFunctions/Upper.htm)(text)